THE MASTER NEGATIVE ,FROM WHICH THIS REPRODUCTION WAS MADE, IS STORED UNDER THE SUPERVISION OF THE LIBRARY PHOTOGRAPHIC SERVICE, ROOM 20, MAIN LIBRARY, UNIVERSITY OF CALIFORNIA, BERKELEY, CALIFORNIA 9 4 7 2 0 FOR ADDITIONAL REPRODUCTION REQUEST MASTER NEGATIVE NUMBER — r PII mA NLL i / 3 i es m—— LAB DAILY Filmed & Processed by the Library Photographic Service University of California Berkeley 94720 lz lz oO EFER * SHE 2 = [& 2: Eas fl2o ba py Me ou — . hh ba is lil his No On X MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS-1963-A METRIC 1 ) : 1,0 1 1 1 1 { DOCUMENT SOURCE: ain Library— LGB. Position D ] Filing “Ui ne. 493 lensno. UNKNOWN DICTIONARY CHE EMISTRY. CONTAINING THE THEORY and PRACTICE of that SCIENCE: ITS APPLICATION TO Fras PHILOSOPHY, | MEDICINE, . aNp RAL HISTORY, ANIMAL ECONOMY: , WIT H Full Explanations of the QuariTies and Mops of Actiox of CHEMICAL REMEDIES: AND TT RE FUNDAMENTAL PRINCIPLES OF THE ARTS, TRADES, and MANUFACTURES, DEPENDENT ON CHEMISTRY. TRANSLATED FROM THE FRENCH. Ww 1TH NOTES, ADDITIONS, and PLATES, THE SECOND EDITION. TO WHICH I$ ADDED, AS A'N APP END I X, i : TREATISE on the Various Kinds of PERMANEN TLY ELASTIC FLUIDS, or GASES. IN THREE VOLUMES, YY QOL I um LON D O N: Printed for T. CADELL, and P. ELmsLy, in the Strand. MDCCLXXV1I. % has Aa A, | "1 N™ cere fed PREF AC. EB BY THE TR A'N-SL A& TOR: . — ¥ - \ HE name of the Author of the French Dic. tionary, of which this Work is a Tranflation, is- not prefixed to it; neverthelefs, it has been univerfally attributed to Mr. Macquzr, Profeflor of Medicine and Chemiftry in the Uhiverfity of Paris, and Member of the Royal Academy of Sciences, who has very juttly acquired amongit, Chemifls a diftinguifhed reputation. Whoever coumn- pares the ftile and doétrines of this writer, in the, works to which his name is prefixed, with thofe of the prefent Dictionary, will not hefitate to give his affent to the general opinion concerning the author. The Work itfelf is not by any means unworthy of Mr. Macquer. It contains a very extenfive know- ledge of chemical hiftory, facts, and opinions, and exact defcriptions of the operations and inftruments of chemiftry. The Phenomena of Chemiftry are well and fully explained, fo far as the prefent ftate a 2 of M2E=07 1 THE TRANSLATOR’s PREFACE. ical knowledge admits. The author has his Work of very extenfive Ty as well as curiofity, by the applications whichis as made of Chemiftry to Natural Hiftory, Medicine, Pharmacy, Metallurgy, and all the numerous 2s and trades, the operations of which depend on che- mical principles. In this comprehenfive p Ie it in- cluded whatever relates to Chemiftry ; and I believe we may juftly affirm, that this Dictionary contains more chemical knowledge than any one book Extane Some perfons may perhaps difapprove of Heng Chemiftry in an alphabetical order. The Au himfelf fays in an Advertifement prefixed or is Work, ¢ that notwithftanding the opinion of fons Jearried perfons who advifed, him to compile a i 1Ct ful of the 1 Dictionary, he had been doubt h oe of that ition; but that, upon far- Ji rer refleétion; it appeared to him lefs exception- « able. and even to be attended with fome peculiar . ’ « advantages.’ a i&tiona- We muft acknowledge that the form of aD is a very imperfect one for eaching a frien oF « knowledge of the relations of cel Eh ings 10 « each other.” But the Chemiftry w ies Vig known is fcarcely entitled to the name o when Si - defined. It is at prefent little more than a olleds of fats, the caufes of which, and hele i So Ly each other, are fo imperfectly Sader ood, thy nut yet very capable either of the {ynt ot i iyi : modes of explanation. Among the ac ve gs dine an alphabetical difpofition, the. Au a 1 any articles have been inferted in the Dictionary, which could not have bien introns in any other method. Flence we may Seren y (oh that the connexion of thefe with the ot jo 7 i . Chemiftry was not pepe A y iftry is incapable ati BE 1a HL of knowledge, no kind { Nt mentions, thatm THE TRANSLATOR’s PREFACE. - of book feems to be more defirable than a Dictionary with references to conneed articles, in which the feveral parts of Chemiftry are treated {eparately, and fo difpofed, that any article, concerning which information may be wanted, may be eafily found, and in which every thing relating to Chemiftry may be inferted. When our knowledge fhall be greatly extended, a more perfect arrangement may be admitted. And now, fince Chemittry is delivered from the obfcure Jargon of alchemifts, and from the narrow limits of one profeffion, namely, the medical, from which it has received much of its advancement; fince it ig now juftly confidered as one of the moft important branches of natural philofophy ; fince it has become a more general object of ftudy, and has lately been fuccefsfully cultivated at home, but efpecially abroad, by perfons who employ the advantages attending rank, opulence, leifure, and philofophical minds, to the acquifition of knowledge, and improvement of ufeful arts; we may hope, that the number of che- mical facts may be daily encreafed; that thofe difcovered may be farther aicertained and illuftrated; and that fome perfon of eminently perfpicuous genius may unfold the laws and caufes of chemical combi. nation and analyfis, collect and methodize the fcat- tered facts, and form the feveral parts of Chemiftry into one regular, conneéted fcience. The merit of the original Dictionary is fufficient- ly evinced by the very favourable reception it has met with, and the high eftimation in which it is held, by Chemifts in all parts of Europe. But in a fubjet perhaps too extenfive for the labours of One Man, feveral articles have been omitted which de- ferve a place in a work that has fo ample a title as the prefent. Some of thefe I have endeavoured to fupply by additional Notes. But the moft material defect arifes from the Author not having been acquainted, a 3 at a — Be AA THE TRANSLATOR’s PREFACE. at the time of publication, with fome late difcoveries concerning thofe permanently claftic fluids, called Faélitious or Fixable Airs, or Gafes, which have been made by Dr. Black, Dr. Macbride, and Mr. Caver- _ difb, and which have thrown much light on a great many chemical phenomena. This deficiency 1 endeavoured to fupply, In the fir Edition, by adding an article on FLixable Air, and feveral occa- ional notes. But fince the publication of that edition, this branch of experimental Philofophy has been fo fuccefsfully cultivated by Dr. Prieftley, M. Lavoifier, and others, that I found myfelf obliged to revife the fubjet, and to make large additions. 1 have accordingly now {fubjoined, as an Appendix, 4 T reatife on the Various kinds of per= manently elaftic Fluids, or Gafess in which I have collected and digefied all the principal obfervations and difcoveries which have been made concerning thefe Auids. And 1 hope this will not be an unacceptable part of the prefent Publication ; as no attempt has been hitherto made to arrange all the knowledge we have acquired on this curicus and important fubject, which at this time engages “he attention of Philofophers in many parts © Europe. "A knowledge of the forms of chemical inftruments being effentially neceffary, and not being capable of being well communicated merely by defcriptions, Plates are therefore added to this Tranflation. Thus 1 have endeavoured to render the Dictionary of Chemiftry more extenfively ufeful than it is even in the excellent original. If 1 have attained this pur- pofe, 1 hope that _thefe volumes may be confidered as a Work, from which Students of Chemiftry may be taught the feveral parts of this ufeful Science; Naturalifts may acquire a knowledge of the pro- rries: of thofe bodies which they are fo curious to difcover, and to diftinguifh; perfons occupied mn THE TRANSLATOR’s PREFACE. in the numerous Arts and Manufatiu os _Chemiftry, may learn the i ps their feveral operations are founded, ‘and be there onaNied o> improve and extend them; and laftly, rom which, as from a Repofitory of Chemical - Knowledge, Philofophical Chemifts may collet the facts and opinions alread I y publithed, and may be affifted to conduct their ay to form thei . of En Ts reson for the farther advancement ADVERTISEMENT. ANY good Treatifes bave been publifbed on Chemiftry, fince that Science bas been cultivated as a fundamental and effential part of Natural Philo- Sophy. But none of thefe publications have the form of a Diflionary. Such a work, however, has been thought fo defirable by [ome men of learning and tafte for Chemical ftudics, that they have advifed me to undertake it. [ confefs, that at firft I did not much approve of their propofal, as I thought that the con- nexion and mutual dependance of the paris of Chemiftry rendered this. [cience incapable of being treated with propriety in an alphabetical order. But on further confideration, and as I advanced in the execution of the work, I perceived that the form of a Dictionary was lefs imperfelt, and even much more advantageous, than it [eems to [ome men of learning. The alphabetical arrangement does indeed feem to interrupt and difconcert the regularity of plan and [iftem, with which a [cience ought to be treated. But this fault may be remedied (as indeed it is in this work, and other good Diltionaries of Sciences already publifbed) by references to correfponding articles; and the connexion may, by this means, be reffored. Be- Sides, ADVERTISEMENT: fides, this apparent want of order allows the readers to form fuch plans to themfelves as they may judge proper; and they may poffibly make a beter choice than the Author would have done. Another advantage attends the treating of a fcience in an alphabetical order. Names of a great number of things occur under their refpeiive initial letters, which would be omitted, in any other method : and thus the fvience is rendered in many refpells more compleat and extenfive. I have only to add, that the readers of this work will eafily perceive, that it isnot a mere vocabulary, or diftionary of definitions; but rather a number of differtations, generally full and extenfive, on all the important objelts of Chemiftry, written with a defign to accomplifb ali thofe intentions propofed in the title- page. A PRELIMINARY A PRELIMINARY DISCOURSE CONCERNING THE ORIGIN sano PROGRESS Oo F CHEMISTRY : S the Hiftory of any Science ought to relate A the labours, the difcoveries, and the errors of the cultivators of that Science ; and to fhew the ob- ftacles which they have been obliged to furmount, and the miftaken paths into which they have {fome- times been mifled ; it cannot therefore. fail of being very ufeful to-perfons engaged in the fame purfuits. This confideration has induced us to give the fol- lowing abridged Hiftory of Chemiftry. But that we may not repeat what fome excellent authors have already copioufly and accurately delivered, we fhall here treat no further concerning the particular Hiftory of Chemifts, than as it tends to illuftrate the general Hiftory of Chemiftry. Our intention is, to fhew the feveral ftates in which this Science has appeared ; the revolutions it has undergone, and the circumftances which have favoured or retard- ed its progrefs ; in a word, we mean to difplay a fummary picture or reprefentation of Chemiftry in different periods, from its origin to the prefent time. Moft authors who have written Hiftories of Che- miftry, have deduced its origin from the higheft an- tiquity. ii PRELIMINARY DISCOURSE: tiquity. They extend their refearches into the firft ages of the world, and pretend to difcover ante- diluvian chemifts. But, like all the hiftorians who have attempted to penetrate through the obfcurity of thefe remote ages, they have found nothing but fable, prodigy, and uncertainty. ¢ do not now live in thofe ages of credulity, when it could be with gravity maintained, and fupported by the authority of apocryphal bocks, that angels and de- mons, {mitten with love of women, difclofed to them the fublimeft parts of Sciences, and the profoundeft fecrets of Chemiftry ; that the book containing thefe fecrets was called Kema, from which Chemiftry de- rived its name ; befides a thoufand other reveries of the fame kind with the preceding, which are not. worthy to be mentioned (2) All that can be truly and reafonably faid on this fubje&, is, that the in- vention of feveral arts which depend on Chemiftry, and are moft neceffary to men, is of the moft remote antiquity. ‘The Sacred Scriptures mention that T%- bal-cain, who lived before the Flood, made inftru- ments of copper, and of iron. This Tubal-cain is believed to be the fame perfon whom the Heathen Mythology afterwards admitted amongft the gods by the name of Vulcan. Thefe hiftorical traces have made Tubal-cain be generally confidered as the firft chemift: a title, which ought to be granted to him with refpe& to that kind of Chemiftry only which is praétifed, not as a {cience, but as an art, or a trade. (a) The author of 4 Courfe of Chemifiry, who follows the principles of Newton and of Stahl, and is the firlt of our writers who have confidered this Science in a manner truly philofo- phical, has ridiculed with as much wit as juftice thefe abfurdi- ties, in an hiftorical difcourfe prefixed to his work ; where the elegance of the file is fuitable to the importance which this Jearned author has given to his fubje&. [Nore of the Author.) No w PRELIMINARY DISCOURSE. iit No doubts will remain on this point, if we re- flect on the nature and progrefs of the human mind. . For, what we call Science is the ftudy and know- ledge of the relations which fubfift betwixt certain fats, which neceffarily muft be fuppofed to have been previoufly difcovered. But the difcovery of thefe facts muft have been effected merely by the de- fire of gratifying the fenfes. For the moft ative and penetrating mind could have done little, in comparifon with the internal perception of a craving want, which muft be obeyed. If it had not been for the pleafing and painful impreffions excited in us by {urrounding objets, we fhould have remained ignorant of their moft common properties. Chance at firit difcovered fome of thefe properties ; and felf- love, from which arifes an inftinét more clear-fight- ed than reafon itfelf, applied them to.ufe. The firft men therefore being neceffitous, muft for that reafon have been the firft artifts. They feized on the be- ginnings of the arts by a natural effort, very differ- ent from that improved reafoning, which alone can give birth to Science, and which requires the {pace of feveral fucceeding ages for its formation and per- fection. We may then conclude that the patriarch Tubal-cain did no better deferve the name of Chemif, than our founders and black{miths. This conclu- fion is conformable with the text of Scripture, where he is called only, malleator and faber ; which is to fay, that he was no more than a mere artift, as all thofe primeval men were, who acquired more knowledge than their cotemporaries. The idea which we here give of the original in- ventors of arts ought not to diminifh the glory due to them. For, as the human underftanding was then in its infancy, and as the Sciences did not yet exift, thefe inventors did all which they could poffi- bly do. Although they were fimple and rude workmen, yet they ought to be regarded as the greateft iv PRELIMINARY DISCOURSE. greateft geniufes of their age. For the ftrength and extent of the underftanding of men are lefs the work of nature, than of the time and of the coun- try where chance has placed them. If Stahl had lived before the Deluge, all the effort of that ge- nius which unfolded the myfteries of nature by means of the moft fublime Chemiftry, would pro- bably have been reduced to invent the method of forging an ax ; and alfo the great Newton, who could meafure the univerfe, and calculate infinites, might rhaps have exhaufted the whole force of his mind in reckoning fo far as the number ten, if he had been born among thofe American nations whofe beft arithmeticians cannot exceed three. Let me therefore repeat it ; the firft perfon who forged iron, or caft brafs, although lefs expert than our meaneft artifts, was notwithitanding a great man, and no tefs deferving our eulogiums than the moit {kilful and profound Chemuft. | Jt has happened to Chemifiry, as to the other arts. Before the invention of letters, an apprentice could only practife what he had learnt from his mafter by oral tradition; and he in the fame man. ner tranimitted his knowledge to his fuccefior, like our prefent workmen, who write nothing, although the art of writing has been fo long known. The moft excellent art of writing was, like moft others, difcovered by the ancient Egyptians 3 and to. this happy era may be truly referred the increafe of hu- man knowledge, and the birth of Seience. Then, a real diftin@tion appeared betwixt philofophers and artifts. The latter proceeded in an uniform courfe, and confined themielves to practice; whereas the former carcfully collected all the knowledge which could extend or adorn the human mind, made it the objeét of their refearches, encreafed it by me- dictation and reafoning, reduced it by writing into order, communicated it to each other, and, In a 5 word, . PRELIMINARY DISCOURSE, v word, laid the foundation of philofophy. Thefe jHuftrious men were the’ priefts and the kings of 2 ople who had wifdom enough to refpeét, and were thérefore worthy to be governed by, fuch mafters. | 2 Amongft thefe royal philofophers, Siphoas is con- fidered by Chemifts as the founder of their Science. He lived, as it is believed, more than xgoo years before the Chriftian era.” The Greeks, who receiv- ed the Sciences from the Egyptians, knew him by the name of Hermes, or Mercurius Trifmegifius. So riumerous is the lift recorded by Clemens Alexan- drinus of this ancient philofopher’s works, (none of which remain) that, in his time, confidérable progrefs muft have been made in the Sciences. Yet among all that lift not one treatife is profeflfedly ‘written on Chemiftry, although we find {ome on every other Science, excepting that one, which has received from him the name of Hermetic Philofophy. In the library at Leyden fome Arabian manufcripts, faid to have been written by Hermes, are more di- rely on the fubje& of Chemiftry. Such, for in- ftance, as that manufcript concerning poifons and antidotes, and another concerning precious ftones. But thefe compofitions are juftly confidered as {pu- rious, and lefs ancient. (4) Probably, therefore, all the (4) Two illuftrious Egyptians of the name of Hermes are re- corded by ancient authors. The elder, who is fuppofed to be the fame as Mizraim, the grandion of Noah, the Hermes of the Greeks, and the Mercury of the Romans, is confidered as the founder of the Sciences. And the younger Hermes, furnamed Trijmegiftus, who lived a thouand years afterwards, reftored the Sciences, afier they had failen into oblivion in confequence of a great inundation of the Nile. Of his numerous works none re- mains, excepting p.rhaps the Smarigdine Table. No lefs than thirty-fix thoufand books are taid to have been written under the name of Hermes. But all thele are not to be attributed to him, For, according to Jamblichus, a cuftem prevailed of {fubicribing all vi PRELIMINARY DISCOURSE. the Chemiftry known in the time of Hermes con- fifted of detached pieces of knowledge, the rela- tions of which were undifcovered, and which therefore could not form a Science; although, at that time, 'Aftronomy, Ethics, and fome other Sciences had made confiderable progrefs, as 1s evinced by the enumeration of the:books of Hermes. We {hall be lefs furprized at this obfervation, when we conder that fome of the moft important phe- nomena of Chemiftry are very little obvious to our fenfes. Hidden as they are by nature under a veil, like the {prings of {ome precious machine, they are difcoverable by thofe only who know to {earch for them, and by eyes exercifed in that fearch. If fome of thefe fingular and remarkable phenomena have been ever difcovered by accident, they could only appear to thefe early philofophers as detached falls, the application and ufes of which could not be perceived, becaufe many other fas, effentially re- jated to thofe difcovered, were unknown. Thefe firft Chemifts, therefore, had no other re- fource than to collet the phenomena which came within their knowledge. Thefe they might repro- duce at pleafure, cither for ufe, or to excite the 1 nt of the ignorant. . Gi ge doubt, was the Chemiftry of the fir inventors of the Sciences; and fuch was the Chemiftry which was taught to Mofes, © infitufies; as the Scriptures fay, in the wiidom of the Egyp- « tians;” and which was afterwards taught to De- mocritus, who went to Egypt on purpofe to learn all books of Science with the name of Hermes. Some of thefe i ibraries ; ; k, entitled, The are preferved in great libraries; and a book, i sce. in Greek and Latin Works of H.rmes, Was publifhed at Venice, in G : 1531, and at «ologne, 620, with notes by Annihal Rofellins, Some authors deny the exiftence of Hermes, and maintain tha his hiftory is allegorical. See Deflande’s Hifloire Critique de a Philofophie, Tom. I. Livre L. ch. the PRELIMINARY DISCOURSE: vif the Sciences at their place of origin. Both of thefé have been numbered among Chemifts: the former; becaufe he “diffolved the golden calf, and rendered it potable by the Ifraelites: the latter, from the teftimony of many ancient authors, and particular- ly of Pliny the Naturalift, who afcribes to Demo- critus a knowledge alfo of the magic arts. (¢) Although we have advanced bat little in the Hiftory of Chemiftry, we cannot proceed without mentioning a fingular madnefs which poflefled Che- mifts. It was a kind of epidemic malady, the fymptoms of which fhewed to what excefs of folly the human mind could proceed, when influenced by a ftrong prepoffeflion. It excited chemifts to furprifing efforts, by which admirable difcoveries were made; but it neverthelefs impeded the ad- vancement of Chemiftry. Finally, the time when this malady began to be cured, which was not fooner than the laft century, is the true era of the revival of this Science, and of its progrefs to per= fection. It is evident, that I mean the paffion for making gold. From the time that this metal has become, by general convention, the reprefentative of the va- lue of all commodities, it has kindled a frefh fire in the furnaces of Chemifts. It appeared natural enough that men {killed in the properties of metals, and accuftomed to fee them take a thoufand va- rious forms, fhould endeavour to produce the moft beautiful and the moft precious of all thefe metals. The, wonders which they every day faw arife from their art, made them conceive hopes of adding this fc) Of all the Greeks who travelled into Egypt to acquire . knowledge, Democritus only was admitted into their myfteries. None of thefe writings are preferved. The Egyptian priefts are faid to have taught him many chemical operations; amongit which were the the arts of foftening ivory, of vitrifying flints, and of imitating precious flones. OL Borrivh. Semec. Epift. 30. new vii PRELIMINARY DISCOURSE. new prodigy to thofe which they had already ef- fected. They were at that ume far from being ca- pable of judging concerning the poffibility of their undertaking ; fince even now that queftion is un- decided. To blame their firft trials ‘would be therefore unjuft. But unfortunately this new ob- je@ of their refearches, was but too capable of producing a ftate of mind very different from the philofophical : it fo engrofled their attention, that they loft fight of other objets: they imagined that to be the ultimate end and perfection of Che- miftry, which in reality was only the folution of one chemical problem : their Science, far from being more extenfive, was concentrated round a fingle point; to accomplifh which they direGted their labors.” The defire of gain became their mo- dive of ation: they were clofe and myfterious : in a word, they had the character of tradefmen ; and if they had fucceeded, they would have been mere makers of gold, inftead of - being intelligent and {kilful Chemifts. But, unfortunately for them, the ¢rade at which they labored exifted only in their imaginations. This circumftance, however, by which they were deprived of a conftant gain, diftin- guithed them from other artifts, and rendered their fituation fomewhat fimilar to men of {cience. They therefore availed themfelves of this fimilarity, and arrogated the titles of Philofophers and of Che- mifts, in preference to all others; as is exprefled by the Arabic particle a/, which they added to the name their fcience ; whence the words Alchemy and Al- ¢heniift, fignifying The Chemiftry, and The Chemift. Thefe men were therefore an intermediate fpecies between philofophers and artits. They had the name of the former, the character of the latter, and were indeed neither the one nor the other. In or- der to fupport their reputation, they wrote books, like the philofophers, on their pretended fcience: Co but # PRELIMINARY DISCOURSE. ix but as charaCer is never to be eff: wrote thefe books {fo obfcurely and ay that they gave no more inftruction concerning on art than if they had not written, Several of them feem fenfible of the reproach to which they are juftly fubject in this refpect, and endeavour to excite attention by declaring at the beginning of their books, that they mean to {peak clearly and plain- ly which, however, they take care not to or It is fomething fingular to fee them, after having for- mally promis] to reveal the moft hidden ferrets, xprefs ir pes Shem elves more obfcurely than any of their We may eafily judge what confiderati people were held in, who did nothing ae nothing : hence their hiftory is as obfcure and eo fufed as their writings. We do not even know the true names of moft of them, the time when the lived, or whether the books attributed to them be genuine or f{purious. In a word, every thing con cerning wen 1s volved in myftery. gh e fhall not then enter into a detail a e- JSius, Zofimus, Adfar, Morienus, Calid, pe Villa Nova, Raymond Lully, Alanus Lillius, Johannes Mennius, and numberlefs writers, or pretended hi lofophers, the enumeration of whole names would be tedious : but we fhall haften over this middle age of Chemiftry, which is the moft obfcure and the moft humiliating part of its hiftory. “Thofe who are defirous of knowing what is related coucernin the Chemiftry. of thefe times, true or falle rs gonial the works of Borrichius, and the Hiflory of ioe a Plilofaphy by the Abbé Langlet de ~ We fhall content ourfelves with obferving in this crowd of alchemical and uniter oh writers, there are a few who have exprefled them. [elves lefs obfcurely on certain experiments, and b 2 have i PRELIMINARY DISCOURSE. have given fome intelligence. Such perhaps are Geber, the Arabian; Roger Bacon, an Englifh Monk, who appears to have known gun-powder, and who was accufed of magic; Raymond Lully, Bafil Valentine, and Ifaacus Hollandus, in whofe writings fomething may be decyphered concerning acid fpirits, antimony, and perhaps other fub- ftances. T hefe valuable hints, which lie {mothered under a heap of riddles, are fufficient to make us regret, that thefe laborious fearchers into the philofopher’s ftone have neglected to inform us of other pieces of knowledge, becaufe they were not immediately related to their object of inquiry. The moft ef- fential fervice which they could have rendered to - Chemiftry was, to relate their unfuccefsful expe- riments as clearly, as they have obfcurely related thofe which they pretend to have been fuccefsful. Such was the ftate of Chemiftry, or rather of Alchemy, till the fixteenth century. At that pe- riod, a famous Alchemift, called Paracelfus, a man of quick parts, extravagant, and impetuous, added a new fpecies of folly to the follies of his prede- ceffors. Being the fon of a phyfician, and himfelf a phyfician, he imagined, that by Alchemy an sniverfal medicine might be difcovered. While he was boafting, that he pofleffed the fecret of pro- longing his life to the age of Methufalem, he died at the age of only forty-eight years. Before him indeed Raymond Lully, and other Alchemifts, had dreamed of an univerfal medicine; but this fa- mous chimera owed its credit chiefly to the eager- nefs and confidence of Paracelfus. This notion, abfurd as it was, gained many par- tifans, and gave double force to the madnefs of Alchemifts ; fo apt are men to believe what they with to be true! Our philofophers, without lay- ing afide their former inquiries into the tranfmuta- tion PRELIMINARY DISCOURSE. «xi tion of metals, and the making of gold, vied with each other in eagernefs to difcover the univerfal remedy; and perfuaded themfelves, that thefe fe- veral miracles might be effected by one chemical procefs. Many of them boafted that their attempts had fucceeded, and ftiled themfelves Adepts. Their books were now filled with receipts for making potable gold, elixirs of life, panaceas or univerfal remedies; but were written in their ufual, that js to fay, unintelligible language. sr So many accumulated extravagancies bad ren. dered Chemiftry a pretended {cience, or, as M Fontenelle ingenioully fays, ¢ a little truth was fo ¢ diluted in a large quantity of falfhood, that it s¢ became invifible and infeparable. To the few « known properties of fubftances their imaginations « added others more dazzling. Metals were fup- a pofed to fympathife with planets, and with the o principal parts of the human body : an alkaheft, “ox menftruum, which had never been feen, was : fuppofed to be capable of diflolving all fub- ¢ frances : the greateft abfurdities were reverenced ¥ hechule fay yore enveloped in myfterious dark- ¢ nefs, in which they were ¢ I 3 s¢ attacks of reafon.” ¢ oneaed agit ee The notion of an univerfal remedy, althoug moft foolith that had entered the heads Sg mits, was however the caufe of the eftablithmeng of rational Chemiitry on the ruins of Alchemy. The fiery and enterprifing Paracelfus had ventured to ftrike out a new road in the art of healing. He declaimed inceflantly againft the ancicnt pharmacy in which were few or no Chemical remedies ; and in a fit of madnefs he publickly burnt the writings of the ancient Greek and Arabian phyficians; vaunting at the fame time, that by his Chemical prepara rions he could beftow immortality. His fuccefs ajthough inferior to his promifes, was however pro- b 3 digious, he " ete emecorastimrs epee eh Fen g om en sii PRELIMINARY DISCOURSE. digious. * He made many furprifing cures; and he applied, with great advantage, mercurial prepara- tions againit the venereal difeafe, which appeared about that time, and baffled the remedies of ordinary pharmacy. 7 The real merit of Paracelfus excited many envious enemies; and the enthufiafm and foolith vanity with which he blazoned his fkill, excited the admiration of others f¥ill more foolifh. Thofe phyficians who had good fenfe enough to avoid thefe extremes, took the middle and wifeft part. They were perfuaded, that much dependance was not to be given to the fayings of a man who was foolifh enough to defpife the knowledge of all others, and to continually boaft of his own difcoveries, and therefore would not, like the mad partifans of Para- celfus, give implicit faith to his extravagant affer- tions. But, on the other fide, they were convinced by his fuccefstul cures, that Chemiftry could furnifh excellent remedies, unknown before that time; and, like good citizens, they endeavoured to difcover thofe remedies by an induftry worthy of praife, fince their motive was the good of mankind. They were, to fpeak properly, the inventors of a new Chemical art, the object of which was: the preparation of medicines: = They wrote what they knew concerning their art, becaufe they were not mere artifts ; and they wrote clearly, becaufe they were not Alche- ifts.. ., 4 Fee were then two clailes of Chemifts, very dif- ferent from cach other. ¥ While the Roficrufian fraternity, Cofmopolitanus, E/pagnet, Beaufvleil, Philalethes, and many others, loft their time, ‘their trouble, and their money, 1n profecuting the foolifh notions of Paracelfus ; many valuable works were publifhed by Crollius, Quer- cetanus, Beguinus, Hartmannus, Vigan, Schroder, Zwel- fer PRELIMINARY DISCOURSE. xiii fer, Tackenius, Le Fevre, Glofer, Lemeri, Le Mort, Ludovicus, and many others, who applied themfelves to difcover and defcribe new Chemical remedies. The principal Faculties of Medicine, perceiving how important it was that remedies thould always be repared in one uniform manner, endeavoured to fix and eftablith the procefles: hence the many Phar- macopeias and Difpenfatories, in which many excellent Chemical operations are defcribed. The greateft part of thofe Chemical arts which are exercifed without literary ftudy, had, in the days of - Paracelfus, arrived to a remarkable perfection, by a progrefs, flow indeed, but long, and unin- terrupted from almoft the beginning of the world. Ores of metals were then advantageoufly effuyed and fmelted. The methods were well known of allaying, diffolving, and refining metals for the purpofes of goldfmiths and of coinage. The compofition of glaffes, of faétitious cryftals, of enamels, and of various kinds of earthen-ware, was underftood. The preparation of colors, and their application to the purpofes of dying, were known. Fermentations, by which wine, beer, and vinegar, were produced; and diffillations, by which the {pirituous, volatile, and aromatic parts of plants were procured for the compofition of effences and perfumes, were underftood and: practifed : but all thefe arts were exercifed by people who knew nothing but what related to their own bufinefs; and as they had never been defcribed, fo they were not all underftood by any one perfon. All the parts of Chemiftry did then exift, but the Science of Chemiftry did not yet exit. Happily the tafte for knowledge, which then began to fucceed the jargon and ignorance of the preceding ages, awakened men of a philofophic mind, and made them fenfible how important it was to wiv PRELIMINARY DISCOURSE. i d publifh fuch a number-of ufeful facts. re raronaed all kinds of obftacles, in order to difcover and unravel the operations of workmen, who, though not Chemis, exercifed the moft effen- i ts of Chemiftry. Bal pee celebrated dil is one of the firft and beft authors of this kind. Born in a village g Mifnia, a country abounding in mines and ois . lurgic works, he has defcribed them exactly an ge pioufly. He wasa phyfician, and cotemporary w Paracelfus, but of a charalter very different. ’ i writings were as clear and inftrudtive as fhe! 0 Paracelfus are obfcure and ufele(s. Lazard, y ers Schinder, Schlutter (4), Henkel (¢), and fome ot rey have alfo written on metallurgy, and have Be. imbe the art of effaying metals. Antony Neri, Dogtor Merret, and the famous Kunkel (f)s who has enric ¥ Chemiftry with many fine experiments, have i fcribed very fully the arts of making glafs, nase S imitations of precious fiones, and feveral other things. : jar luable Chemifts whom we have mentioned, os a who fucceeded them, and whom we diftinguith from the Alchemifts, were not Howeyes entirely free from the illufions of Alchemy. ” o true it is, that an obftipate and inveterate malady hover difappears ,at once, without leaving traces bein v Thus, fince the time of Paracelfus and Agrico a we have had many authors, in fome refpedts rational. Chemifts, and in others Alchemifts, Keyfler, Caflius, into French : of Schlutter have been tranflated into TL aw on the obfervations of the Tranflator, tg 1 obligations, : wim Ce — ny been tranflated into French oe Baron d’Olbach, one of the moft zealous and illuftrious f Fregch Chemifiry. De The A of Neri, Merret, and Kunkel, are tranflated into krench by Bares d'Olback. into Lrench by PB Rocfebiss, PRELIMINARY DISCOURSE. «xv Roefchius, Orfchal, Sir Kenelm Digby, Libavius, Van Helmont, Starkey, Borrichius, are of this number. But they have fufficiently made compenfation for this fault by the number of interefting experiments which they have related. As in the latter times of the Authors above-men- tioned, the Alchemical phrenzy began-to draw near its crifis, it was attacked by many powerful anta- gonifts, to whom rational Chemiftry has many obli- gations ; fince by their writings, they contribut- ed to refcue that {cience from an evil which at once difgraced it, and retarded its progrefs. Amongit thefe authors, are moft diftinguifhed the celebrated Kircher, a Jefuit, and the learned phyfician Con- ringius, who wrote with ‘much f{uccefs and reputa- tion. \ We are at length arrived at one of the moft brilliant eras of Chemiftry: I mean the time when its feveral parts began to be colletted, examined, and compared by men of genius {ufficiently ex- tenfive and profound to comprehend them all, to difcover their principles, to obferve their relations, to unite them into one body of rational doétrine, and to lay the true foundation of Chemiftry, confi- dered as a Science. Before the middle of the laft age, this edifice was not begun to be erefted, but the materials only had been colleéted. Fames Barner, phyfician to the King of Poland, was one of the firlt who arranged into order the principal Chemical experi- ments, and added rational explanations. His work is entitled Philofophical Chemifiry. All the phe- flomena of this Science are there referred to the fyftem of acids and alkalis which Tachenius had eftablithed, but which he had abufed by extending too far: a fault very pardonable, when we confider how difficultit was for him to avoid it, who had dif- covered xvi PRELIMINARY DISCOURSE. covered truths fo general and fo fertile in confe- quences as are the properties of thefe {fubftances. Bobnius, a Profefior at Leipfic, publifhed alfo a valuable Treatife of Rational Chemiftry ; but the reputation of thefe Philofophical Chemifts has been almoft eclipfed by the famous Becher, Principal Phyfician to the Electors of Mentz and of Bavaria. This man, whofe genius equalled his knowledge, appears to have feen, with a fingle glance, the immenfe multitude of chemical phenomena. By refleGing on thefe important objects, he invente the beit and moik fatisfactory theory which has been ever publifhed. This theory has had the honor of being adopted and commented upon by the reateft and moft fublime of all the Philofophical hemitts. By . thefe titles the illuftrious Stabl, Principal Phyfician to the late King of Prufiia, deferves to be diftinguifhed. Born, as Becher Was, with a {trong affion for Chemiftry, which fhewed itfelf in his early youth, he nherited a genius fill {uperior to that of Becker. His imagination was as lively, as brilliant, and as active as that of his predecefior; and he had, befides, the ineftimable advantage of being regulated by that philofophic and temperate wifdom, which effectually preferves from enthufiafm and illufion. The theory of Becher, which he has adopted slmoft entirely, has become, in his writ- ings, of all theories the moft enlightening, and the moft conformable with the phenomena of Che- miftry. Very different from thofe fyftems which are produced by imagination, without truth, and which experience deftroys, the theory of Stahl 1s the fureft guide that we can take for our conduct in Chemical refearches ; and the numerous experiments which are every day made, far from invalidating it, become new proofs for its confirmation. 5 a ext PRELIMINARY DISCOURSE. xvii. “Next to Stabl we place the immortal Boerhaave ; though he excelled in a different way. This powerful genius, the honor of his country, of his profeffion, and of his age, threw light upon every fubje&t which he treated. To the view which he took of Chemiftry we owe the fineft an methodical analyfis of the vegetable a % io admirable Treatifes on Air, on Water, “on Earth and particularly that on Fire, which is an aftonith ing mafter-piece, fo complete, that the human un- derftanding can fcarcely make any addition to it. Although the theories of the great men we have mentioned may contribute infinitely to the advance- ment of Chemiftry, by explaining the caufes and relations of the phenomena of that Science; we muft however confefs, that they may produce a very contrary effet, if we deliver ourfelves up ‘to them with too much confidence, and extend their application beyond their true limits. Theories can only be ufeful fo far as they arife from experiments already made, or lead us to new ones ; for reafoning may be confidered as the eye of a philofopher, but experience is his feeling ; and this latter fenfe ought conftantly to rectify the too frequent errors of the former. If experiments, undireted by theory are only a blind feeling; theory without experi- ments 1s a deceitful and uncertain vifion. Accord- ingly, the pa Spor difcoveries that have e in chemiftr 1 jo Thge In Sank y, have been owing to the A very convincing proof of this truth a in the works of the illuftrious literary Se ote whofe origin may be confidered as the origin of experimental philofophy, and the true era of the expulfion of the barbarous jargon of the Schools of the illufions of judicial Aftrology, of the extra vagancies of Alchemy, which were only chimerical {pecu- 1 PRELIMINARY DISCOURSE. of proof, or confufed heaps ‘ade xvi {peculations, deftitute of inclufive facts. The learned and profound Memoirs of thofe celebrated Societies will be ever the model of thofe who intend to advance the progrefs of Science; fince there we always fee experiments giving ftability to theory, and theory giving light to expe- | riment. We have now the advantage of feeing the beft days of Chemiftry. The tate of our age for philofophical matters; the protection of Princes; the zeal of a multitude of illuftrious and intelligent fons attached by inclination to the ftudy of this Science; the profound fkill and ardor of modern Chemifts, whom we do not attempt to praife, be- caufe they are above our eulogiums ; feem all toge- ther to promife the moft brilliant fuccefs. We have (een Chemiftry drawing its origin from neceffity, and receiving a flow and obfcure encreafe from avarice. To true Pp hilofophy it was referved to bring it to perfection. A DICTIONARY i A DICTIONARY 0 CHEMISTRY. F AC1D BSORBENT. (a) ACETOUS. (4) ACESCENT. - This word may be empl yed : ma : ; ployed to denote ich §ysher is turning four, Sit is to fay, eb ightly acid. See Acip. {¢) ’ i. ACID. Acids are of all faline fubftances the moft fim« ple, and confequently ought to be con principles. "Their name is derived odors po Sagi B acid or four. One of the marks by which they are erly (a) ArsorsenTt., Thole carts are T. are called i capable of being combined with it, fhe Kia Febt asthe; afhes of burnt vegetable and animal eR, Hage ie, 834 earth of alum. This clafs of earths might be ws. pa dy demominied alkaline earths, See EARTH, Mac- (5) Acerous. Acetousacid isthe fa i b) Acer me as Ames is she Sermentzson by which ins Ee a r is 1 ca; = Abin dy er made by means of vinegar. See Ving- ¢) The word acefcent can only be i y be properly appl os Bt of thefe ecHings. The on] J pha ng wy er of the words, acidulous or fubacid. ! pen Vou. I, h known, «ili PRELIMINARY DISCOURSE. fpeculations, deftitute of proof, or confufed heaps of inclufive facts. The learned and profound Memoirs of thofe celebrated Societies will be ever the model of thofe who intend to advance the progrefs of Science; fince there we always fee experiments giving ftability to theory, and theory giving light to expe- riment. We have now the advantage of fecing the beft days of Chemiftry. The tafte of our age for philofophical matters the protection of Princess the zeal of a multitude of illuftrious and intelligent perfons attached by inclination to the ftudy of this Science; the profound fkill and ardor of modern Chemifts, whom we do not attempt tO praife, be- caufe they are above our eulogiums ; feem all toge- ther to promife the moft brilliant fuccefs. We have {een Chemiftry drawing its origin from neceffity, and receiving a flow and obfcure encreafe from avarice. To true philofophy it was referved to bring it to perfection. A DICTIONARY ~Mcetous ether is an ether made by A DICTIONARY ha CHEMISTRY. : AC1D BSORBENT. (4) ACETOUS. (3) fen A ESCENT 4 ms word may be employed to denote a m3 Vr py turning four, that is to byw gy wiich ghdy aad. $2 Ac. {c) ’ ’ which is » Acids are of all faline fubftan WA CoRfendy ought to be ee on fins £ ep es. heir name is derived from their tafte ‘wonaart 33 a8 or four. One of the marks by which they ey (a) AssorBENT. Thofe earths ai T. { s are called i sre qapable of Zong Somlsined with aide Tarte Rik > of burnt veget ar : 0 magnefia, and earth of alum. Be is ciate oF i bis oo more properly d i A wi Fr pe 3 Somomingied alkaline earths, See EARTH, Ma G= y 2 2 t . . * fermentation is that fermentation by which vinegar is produced m . GAR, and ETHER. eans of vinegar. See Ving- (¢) The word acefc the lt 05 nowy Sin can only be properly applied to denote 2 5. Th either of the words, us ge ay by eaprefind by You. I. known, AC 1D is thei ing i ylue co known, is their property of changing into red the bl lors of an infufion of flowers of violets, or of the tincture f heliotropium. (4d) j o If rire 2 wnt from all moifture or water, and from all other fubftances not neceflary to their {aline eflence, : Acips generally change the blue color of vegetables, aR of ie iy "i of their infufions, to a red ; and they heighten the red color of thefe fubftances ; whereas alkalis change the blue colors of vegetables to a green. Hence the fyrup of violets, the tin&ure of heliotropium, and other Ife fions of vegetables, have been generally ufed to diftinguifh the acid or alkaline qualities of bodies. This criterion 1s, Homers fubje&t to many exceptions. The volatile fulphureous acl whites blue and red flowers. Several neutral {alts have been obferved to aét upon, thefe colors. Alum 1s {aid by fome BLhons to render fyrup of violets red ; and by others, green. The di 2 rence may have arifen from the excefs of alkali employed in the preparation of alum ; for it is known that a lixivium of aluminous earth cannotbe well cryftallized without addition of fome Wlesline ley. The Count de Saluces has even obferved, that the color © fyrup of violets was at firft rendered purple by means of alum, and that it afterwards became green. A fingular exception to the above general rule is furnifhed by the lignum nephriticum the blue color of an afin % Wilh Ssenvriel by acids to a is again reftore an alkali. oho a) or reluce! has, Ne the Turin Memoirs, publifhed an account of experiments made to difcover the caufe of the changes of color induced on fyrup cf violets by mixture with different {ubftances. From thefe experiments, he found that a greet color was given to the fyrup by the following fubftances, mof of which are confidered as neuntralifed ; Vitrio ated tartar, Glau- ber’s falt, vitriol of copper, calcined bones, witre, fea falt, [ugar of lead, turpeth mineral, calcined gypfum : thata red color was given to the fyrup by jpirit of witriol, marine acid, and cream of tartar : ‘that aqua fortis produced a golden yellow color: that alum pro- duced a violet color, which afterwards changed to a dirty Pee : that artificial plume-alum gave a cherry-color : and that the » or of the iyrup was rendered firft green, and afterwards of & orange-yellow by oil of tartar, and by guicklime, and by volatile alkali. “He infers from thefe faéts, that the rednefs given to. :olets proves a fuper-abundance of acid in the fub- pr of via redone that ns but that the green color 1s a very equivocal proof of the prefence of an alkali, and 3a ther indicates fome neutral fubftance, if the green ele ermanent ; for if any matter be added in which a fixed or volatile alkali predominates, the green color, which at firft ap- pears, is afterwards changed to a yellow. they A C1 D they would appear under a concrete or folid form. But ge- nerally they are liquid; becaufe their affinity to water is fo great, that when they contain no more than what is necef- fary to conftitute them falts, they are ftrongly difpofed to feize more water, whenever they can touch it; and as the atmofphere is ‘always loaded with watery vapors, the con- tact of the'air is folely fufficient to render acids fluid, by their rapid union with its moifture. Acids have a general tendency to unite with almott all fubftances, particularly with thofe which are either fimple, or not much compounded ; as phlogifton, alkaline falts, fixed and volatile earths, (efpecially thofe called abfor- bent), metallic fubftances, water, and oil. Many fubftances are by chemifts called acids, becaufe. they poflefs thofe general properties which we have men- tioned. But thefe fubftances differ from each other by pro- perties peculiar to each. . As acids from their tendency to unite, and to remain united with almoft all other bodies, are never found fingle ‘and pure, but mut be obtained and feparated by artificial operations from the bodies with which they happen to be combined ; they have been diftinguithed by authors inte clafles, according to the fubftances whence they are ex- tracted. Thefe clafles are mineral acids, vegetable acids, and animal acids. In Mr. Geoffroy’s Table of Affinities, thofe of acids are marked in the following order: fixed alkali ; volatile alkali ; earths ; metallic fubftances. (¢) Very (e) Under the article ArriviTY are fubjoined two Tables of Affinities, one by Geoffroy, and the other by Gellert, together with an explanation of them. Here it may be ety to mention, in order to the underftanding of the text, that thofe fubftances are placed firft in order which have the ftrongeft af- finity, that is, which are moft difpofed to unite with the fub- ftance whofe affinities are compared together. Thus, accord- ing to Mr. Geoffroy’s Table, quoted in the text, acids are more difpofed to unite with fixed alkali than with volatile alkali, earths, or metallic fubftances ; and more difpofed to unite with volatile alkali, than with earths and metallic fubftances ; and laftly, are more difpofed to unite with earths than with me- tallic fubftances. The affinities of acids, that is, their comparative powers of union with other fubflances, are in the following order, begin- ning with the greateft. 1. Fixed alkali. 2. Calcareous earth: 3. Volatile alkali, and magchs: the affinities of which to acids 2 are A C1 DH Very concentrated acids taken internally in a dofe fomé- what large; for.inftance, an ounce, or even much lefs, when the acid is fufceptible of great concentration ; are ‘corrofive and genuine poifons. Their beft antidotes ase alkaline fubftances, either faline or earthy, oils, alkaline foaps, large quantities of mild drink, as water, milk, mu= cilages. 'Thefe muft be given copioufly and fpeedily. Small dofes of acids diluted with much water, fo as to~ be agreeably acidulous, and blunted by fome mild fub- ftance, as fugar, are excellent cooling and aperitive me- dicines, fit to quench exceflive thirft, and leflen the acri- mony of the bile. They are chiefly ufeful in alkalefcent difpofitions, and in putrid, inflammatory fevers. Their whole 2&ion feems to be exerted on the primz viz; for they are rendered unactive by the powers of digeftion, by means of which they are combined with the earthy and oily parts of aliments and digeftive juices.. The would be certain poifons if they pafled into the blood-veflels with their acid qualities, at leaft with their acidity undiminifh- ed. They would coagulate the blood, and would greatly irritate the nervous and fefible pants. Melpighi Killed a dog by inje&ing into the veins fuch a quantity of nitrous ai, ye Ye tn have hurt if it had been fwallowed. Acids employed externally thew fimilar qualities, but more fenfibly than when impaired by the digeftive powers. They are ufeful againft alkalefcent putridity. (f) SID are nearly equal. 4. Irom, zinc, copper, and perhaps fome other metals. 5. Earth of alum. 6. The remaining metals. (f) I. The common properties of acids are, 1. They may be united with water. This is not merely a dilution of acids, for by uniting concentrated acids with water, heat is roduced ; and the mixed fluid acquires a {pecific gravity, different from the intermediate gravity of its component parts. From this union, therefore, a new compound is formed. 2. Concentrat- ed acids produce cold, when mixed with ice. The vitriolic acid has been faid by fome authors to produce heat by mixture with ice. But the heat thus excited has been occafioned by too great a quantity of vitriolic acid in proportion to the ice. Fora certain’ proportion of that acid being added to ice, thaws the ice, and produces cold, like the other acids : But if more vi- triolic acid be added to the ice thus thawed, it will have the - fame effe@®, which, as we have obferved, is occafioned by the adding of this acid to water ; that is, heat will be produced. 3: They may be combined with fpirit of wine, See ET oe. 4. The A CLD ACID (ACETOUS). 8c VINEGAR. ACIDS (ANIMAL). This name is given to acids _ obtained from certain animal matters; as butter, fat, blood, ants, and moft flies. | Thefe acids have been too little examined to enable us to judge whether they be eflentially different from thofe obtained 4. They may be combined with abforbent earths. 5. They may be combined with alkalis. 6. They may be combined with metallic fubftances. Although every acid does not di- reétly diflolve every metallic fubftance, yet probably by con- centration-or dilution of the acid, divifion of the metals by me- chanical and chemical methods, by application of fufficient heat, and other means, every metal may be aéted upon by every acid. 7. When much concentrated, they may be combined with phlogifton, and with oils. 8. When they combine with thefe fubftances, they difengage from them all or Po of the fixable air which they contain. 9g. They foften and diffolve the folid parts of animals, 10. They coagulate moft of the liquid parts of animals. 11. They change to red the blue, and heighten the red colors of vegetables, excepting volatile fulphureous acid, which deftroys thefe colors. Probably this change of color pro- ceeds from the action of acids upon the oily parts of vegetables ; for oils are rendered red by acids fufficiently concentrated. 12, They refift fermentations, "13. They are not capable of being frozen by fo {mall a degree o2 cold 3s water is. II. As acids fo powerfully attra& water, that they are never found pure and dry, but always in a fluid ftate, when uncombined with earths, alkalies, or metals, we cannot eafily afcertain the quantity of acid contained in acid liquors. Homberg has at- tempted to eftimate the quantity of acid contained in the acid fpirits of vinegar, nitre, fea-falt, and of vitriol, b combining thefe liquors with falt of tartar, fo as to form neutral falts, imagining that the weight gained by that alkali from its union with acids, or the difference betwixt the weight of the falt of tartar and the neutral falt produced, was equal to the weight of real acid contained in the quantity of acid liquor employed. But as he did not confider, that the gas expelled from falt of tartar, during its combination with acids, makes a very con- fiderable part of the weight of that alkali, the inferences from his experiments are not juft ; and the real quantity of acid con- tained in an acid liquor, is fo much more than the quantity in- ferred by him, as the whole weight of the gas difengaged from the {alt of tartar. The quantity of gas contained in falt of tartar varies much according to the method of its pre- paratiop, and other Circumfianes ; and the quantity alfo of water 3 retained A C+D obtained from vegetables.” But we are certain, that they differ in the fame circumftances as the vegetable acids do from mineral acids; and probably, this difference proceeds from the fame caufe which contftitutes the difference be- twixt the végetable and mineral’acids ; namely, the com- bination of oily particles with" the former. ‘(g)* : The retained by different neutral falts in their cryalfization, being the eftimate made by M. Homberg. - Til. The #nown acids are, 1. Vitriolicacid. 2.’ Nitrous acid. 3. Marine acid. 4. Acetous acid. 5. Vinous acid, or tartar. 6. Effential acid of vegetables. 7. Acid obtained by dittilla- very different, we may eafily perceive another fource of error in tion of vegetables. 8. Acid of bitumens. g. Acid of borax, 10. ‘Acid obtained by diftillation of oils, refins, ‘and fats. . 11. Phofphoricacid. 12. Acid of antsandotherinfedts., 13. Acids of healthy and of difeafcd flomachs of animals.” 14. Acid of Ji matter of difeafed animals. 15. Acid of fluors. erhaps the number of acids is much larger’; or perhaps fome of thefe are only modifications of other primary acids ; orlaftly,’ as Stahl fuppofes, they are all modifications of the one only pri- » the article SALT. | : (5) The acid of ants may be perceived by fimell, on turning up an ‘ant-hill in {pring of fummer.’ When’ thefe infets are ir~ ritated, they difcharge a fluid which has an acid tafte and fimell. Water, or {pirit of wine, in which they are agitated, becomes mary acid, ndmely, that of vitriol. . See the theory of acids under acidulous. Part of ‘this acid" is fo volatile as.to rife’ by diftilla-- tion with {piri of wine, in which ants had been ‘immerfed ; but the greateft part of it is fo fixed, as to remain united with’ the refiduous phlegm. All the acid may be extraéted by water, and rendered capable of rifing by dittillation’ with that fluid in a water-bath. From 24 ounces of freth ants were obtained by diftillation, without addition, eleven ounces and two drams of acid'fpirit, fome urinous falt and fpirit, fome empyreumatic oil, ang a refiduum, confifting of earth and fixed falt. 'T his acid is found to have the general properties of acids. With fix- ed alkalies it forms neutral” cryflals, ‘oblong, and deliquefcent. Thefe cryftals being diftilled by a violent fire, yielded a liquor {carcely acid, and another liquor urinous or ammoniacal, From the refiduum diffolved in water, by filtration and evaporation, were obtained large cryftals which did not deliquiate, and had the general properties of fixed alkalies. In this éxperiment the acid feemed to difappear. But by pouring oil of vitriol on thefe alkaline cryftals, white vapors were difengaged, although no acid fpirit could be obtained by diftillation, From thefe white vapors, dud from the facility with which this falt cryftallizes, 4 Mr. ACID The phofphoric acid, obtained from urine, appears, for the fame reafon, to belong to this clafs of animal acids. But it has properties fo different from thofe of all other acids, that it deferves to be confidered as a diftinct acid, See PHOSPHORUS. ACIDS (CONCRETE). Thefe are faline, folid fubftances which have the general properties of acids. Such are, cryflals of tartar; effential [alts of vegetables, par- ticularly of thofe which are acid; the wolatile acid falt of amber, and of fome other bitumens ; and flowers of Ben- amin. ! ACIDS (FLUOR), Are thofe which are generally, or always in a fluid ftate ; fuch are the volatile vitriolic, nitrous, marine acids, and thofe obtained by diftillation from vegetable and animal fubftances. ACID of FLUORS. Se FLuors. ACID (MARINE). Thisis fo called, becaufe it is generally obtained from fea-falt; though it may be alfo procured from Sal-gem, or foffile falt, and from the {alt of Mr, Margraaf, from whom thefe and the following experiments on the acid of ants are extra&ted, fufpects the exiftence of a latent acid, The acid of ants formed with volatile alkali an ammo- niacal fluid, which, like the combination of the fame alkali with vinegar, could not be reduced to a concrete or folid ftate, With quicklime, chalk, and coral, it formed dry cryftals. This acid did not precipitate filver, lead, or mercury, fram nitrous acid ; hence it has no analogy to marine acid. Nor did it precipitate quicklime from marine acid ; and hence it has no analogy to vitriolic acid. As a menftruum, this acid afted weakly upon cepper, and firongly upon iron and upon zinc ; but it did not act, or very little, upon filver, lead, tin, regulus of antimony and hifmuth, Its combination with iron cryftallized ; in which refpet it differs from vinegar. It diffolved the calxes of copper, filver, zinc, and lead ; but not the calxes of tin, regulus of antimony, bif- muth, or of merciry, which laft calx it converted to fluid quickfilver. Upon the whole (fays Margraaf), we may per- ceive a refemblance in many refpeéts, though not in all, betwixt this acid and the acetous, See the Memoirs of the Berlin Academy, vol. 4. 1749, or the Qpufcules Chemiques de Mr, Margraaf. Infos armed with flings, as bees, wafps, and hornets, when irritated, difcharge an acid liquor. A very ftrong acid has been obferved by M. Bonnet to be ejeited by a caterpillar, which he diftinguithes by the name of grande chenille du Jaule a queu Sfourchue. See the Mem. des Sgavans Etvang. Tom 2. and Philef. Tranf. for 1743. Y B 4 faline re en we —— ai ene re. dE RT WE ons — — er - whim - — g - a —— ACID faline fountains and pits, fince all thefe falts do not differ from fea-falt, but in their origin. ‘The marine acid, as well as the nitrous and vitriolic, is never found alone and pure; but it is always com- bined with an alkali, fo as to form a neutral falt, which is Sifilved copioufly in the fea, to which it gives a faline talte. This neutral falt is alfo found cryftallized in large tranf- arent maffes within the earth, and is then called Sal-gem, or foffile (alt. It is alfo diffolved in the waters of fome wells or fountains, which may be owing to thefe waters communicating by fubterraneous paffages with the fea, or to their paffing through mines of Sal-gem. The marine acid has all the general properties of faline acid fubftances. It differs from the vitriolic acid in the following circum- ftances : it is more light and volatile; it has {mell and color; it emits vapors; it has lefs affinity with fixed alkalies and abforbent earths; and, like the nitrous acid, it forms with abforbent earths no falts but fuch as are deliquefcent. It differs from the nitrous acid by its color, which is more yellow and lefs red ; by the whitenefs of its vapors, which are vifible only in open air; by its {mell, which refembles faffron ; by a weaker affinity with abforbent earths and fixed alkalies. (5) The marine acid cannot be fo much concentrated as the vitriolic and nitrous acids, becaufe it is much more volatile, This acid cannot be fo eafily combined ‘with phlogifton as the vitriolic and nitrous, and we are not certain that fome medium is not requifite for fuch a combination. Although the properties of the marine acid are as well ‘known as. thofe of the nitrous and vitriolic, yst chemifts are far from underftanding the nature of this faline fub- ftance equally well. Becker, according to his theory of acids, attributes the diftinguithing properties of the marine acid ta that principle which he calls mercurial earth. But he fupports his opinion by no other proofs, than by fome (5) Marine acid differs from the nitrous in another inftance, befides thofe mentioned in the text. It readily diffolves metallic calxes, which are little affe€ted by nitrous acid. Hence it ex- traéts from moft colored earths and ftones the metallic calxes, by which the color of thefe fubftances is produced. | | appear : A'C1D appearances caufed by the union of this acid with metallic fubftances, in which alfo he fuppofes this mercurial earth’ to be a component part, But as the exiftence of this: mercurial earth in marine acid, or in metallic fubftances,. is not demonftrated, nor even fufficiently indicated; and as Becker has explained himfelf very obfcurely and confufedly on this fubjeét, what he has {aid does not merit a deliberate difcuffion. - Stahl, therefore, who was too judicious to be fatisfied with appearances and probabilities, abandoned, in fome meafure, this part of Becker’s theory, and only exprefles a wifh that the exiftence of the mercurial earth could be as well afcertained as the exiftence of phlogifton. This great chemift, however, appears to be convinced of the primary identity of all faline fubftances; that is to fay, he believed that they all were the vitriolic acid dif- guifed by fome mixture. He affures us, even, that he has been able to tranfmute acids into each other; that is, to change the vitriolic acid into the nitrous and marine ; and to reduce thefe back again into the vitriolic. But he has not publithed his experiments on this fubje&, perhaps becaufe he had not fufficiently afcertained the procefles, or that he chofe to referve to himfelf fuch important dif- coveries. © The poffibility, therefore, of thefe tranfmuta- tions of acids is not yet determined. (7) : The properties of the marine acid, above-mentioned, “indicate nothing more than that it participates of the na- ~ ture of both-the vitriolic and nitrous acids. Its combination with phlogifton, which, of all its pro- perties, might afiift us moft in our inveftigation, has not been fufficiently explained. The unfuccefsful attempts made by M. Margraaf, a celebrated chemift of the Academy of Berlin, to combine the marine acid pure and crude, as he calls it, with phlogifton, with a view to compofe phofphorus, are fo many frefh caufes of uncertainty, and additional motives to endeavor to illuftrate this important objet. Se Pros- PHORUS. Marine acid, combined to the point of faturation with marine alkali, called alfo mineral or foffile alkali, forms a neutral falt, cryftallizing in cubes, of an agreeable, faline tafte. See Common SALT, under the article SALT. (7) Concerning the identity of acids, fee the article Sarr. Concerning the tranfmutation of marine acid into the acid of nitre, fee alfo Acip (NiTrOUS), | With A C1 D With volatile alkali it forms a neutral, eryftalli. Jor pungent fuls, Tis fe is Fi tlae. kp in blimed with a certain degre . i nis a FRSA e of heat. It is called Sal etallic fubftances are in general more difficultly dif- folved by the marine than by as vitriolic and Waly ar beens the firft has lefs affinity than the other two with ph bg! on; which is the medium of union betwixt metals Marine acid, when fluid, however much concentrat and affifted by any heat, cannot diffolve gold, ver, platina, or mercury, in their natural or metallic ftate. It combines, however, very well and intimately with filver and mercury by two methods. One of thefe is called the dry method or cementation, becaufe the acid then, in fome meafure, is dry, and expofed to the greateft heat it is capable of receiving. &8¢¢ PARTING (CONCENTRATED) and SusLIMATE (Corrosive). The fecond method is Salley Sadun itit, and confifts in feparating thefe metals eir {olution in nitrous acid. SL PRs CIPTTATE (WHITE). t Rel ivatunits, is acid, when pure and unmixed, cannot known method diffolve gold or platina. But oo it bs mixed with the nitrous acid, it forms a menftruum called aqua regia, which readily diffolves thefe metals. See AQua Recia. From combinations of aqua regia with gold or platina, metallic falts are formed fufceptible of cry alloza, tion. See GoLp, and PLATINA. (4) Pure marine acid diflolves fufficiently well tin, lead copper, iron, zinc, and bifmuth; and lefs eafily re ulus of antimony : and it forms with thefe metals different falts, the properties of which fee under the articles Tin Lea, &c. (J) ’ . The general phenomena moft remarkable in the combi- nation of marine acid and metallic matters, are: 1. It diffolves thefe fubftances with lefs heat and effer- _ (#) By two methods gold and platina may be rendered foluble in marine acid: 1. by previous folution in aqua regia, and precipitation from that menftruum by means of alkali; or 2. by a previous calcination with tin or bifmuth. CY (/) Marine acid, when boiling, diffolves arfenic. Regulus of cobalt, and the femi-metal calied nickel, are alfo foluble in marine acid : the folution of the former is of a reddith yellow color, which is changed to green by application of heat; and the {olution of the latter is of a dcep green color, ’ vefcence, ACID vefcence, and with fewer vapors, than nitrous acid does. “This obfervation is true, even with refpe& to thofe metals which it diffolves moft readily, as copper and iron. 2. It forms with all the metals which it diffolves, ex= cepting iron and copper, falts capable of cryftallization. The caufe of this property is, that generally it takes from metals much lefs of their phlogifton than the nitrous acid does. The metals with which it contralts the ftrongeft union, as filver, lead, mercury, and the regulus of anti- mony, are actually thofe with which it unites moft diffi- cultly. We mutt here obferve, that marine acid feparates filver, lead, and mercury, from the nitrous acid in which they had been previoufly diffolved ; and when it 1s once united with thefe metals, they adhere more ftrongly to it than they did to the nitrous acid. This has given occafion to Becker and other chemifts to advance, that in marine acid, and in the laft mentioned metals, there is more of that principle which they call mercurial earth, than in any other acids or metals. And to this abundance of mercurial earth they attribute the ftronger connetion of marine acid, and the mentioned metals, which are diftinguithed from all others by the appellations white, lunar, and mer< curial. 4. Marine acid has the property of volatilifing, or carry- ing off with it in fublimation or diftillation, entirely or partly, the metals with which it is united, thofe particu- larly with which it forms the ftrongeft union, as mercury, regulus of antimony, filver and lead. See SUBLIMATE (Corrosive), Luna Cornea, BUTTER of ANTIMONY, and PLumBum CorRNEUM. 5s. Marine acid, though in fome refpeés lefs ftrong than the vitriolic or nitrous, forms with metallic fubftances, -and particularly with the laft mentioned metals, with which it adheres moft firmly, metallic falts, much more ‘corrofive than thofe formed by the other two acids. See CAUSTICITY. The greateft part of thefe phenomena, peculiar to marine acid, evidently proceeds from the difficulty with which it unites with phlogifton, and from the fmallnefs of the quantity of that principle which it takes from metallic fubftances, However, thefe phenomena, thus colleted, may, by being compared together, furnifh matter for curious fpe- culations concerning the famous mercurial carth of Becker, | which, ACILD ,which, according to him, is the third principle of metallic fubftances. Befides, in moft folutions of metals by marine acid, a fingular {mell, refembling the fmell of garlic, or of arfenic, is exhaled: but, according to Becker, arfenic contains abundantly the mercurial principle. ~The difficulty with which marine acid combines with the inflammable principle, is the reafon why this acid acts fo little upon oils and oily fubftances. It feems to have no power over thefe fubftances when it is fluid and united with a certain quantity of water. What it would produce, if it were artfully applied to thefe oleaginous matters in its higheft degree of concentration, with the help of confider- able heat, is not known. Very interefting refearches re- main yet to be made upon this fubject. : It appears that the inflammable principle, when in- timately united with water, as in ardent fpirits, is in the favorable ftate for combination with marine acid ; although many more difficulties are found in making this combina- tion with the marine acid, than with the vitriolic or nitrous. Marine acid, mixed with the {pirit of wine in all pro- portions, and frequently diftilled with it, is much lefs intimately combined than the other two acids, and propor- tionably lofes lefs of its acidity than they do. See SPIRIT of SaLT (DuLcIFIED). _ Lately, however, marine acid has been applied to fpirit of wine in fuch a manner, that from their union refults a liquor which has the diftinguithing properties of ether, and is a true marine ether. 7. Beaumé, an able artift, and excellent obferver, was the firft who publithed that he had fucceeded in making this combination. His method was by applying the vapors of highly concentrated marine acid to the vapors of fpirit of wine, by means of a convenient _apparatys of veflels, The detail of this fine experiment may be feen in his Differtation on Ether. See ETHER (MARINE), Afterwards, an illuftrious and learned lover of chemiftry * has found a method of making marine ether much more eafily, and more abundantly, by diftilling along with fpirit of wine the figaking [pirit of Libavius, which is nothing “more than highly concentrated marine acid, charged with 2 confiderable quantity of tin, which it had carried up with it in diftillation, = See SPIRIT (SMOAKING) of Lisa YiUs, ®.The Marquis de Courtanvaux, M. Pott, Rcip M. Pott, in his differtation de acids falis vinofo, and other chemifts, mention the mixture of fome metallic falts, containing concentrated marine acid, fuch as butter of antimony. with fpirit of wine. The phenomena which accompanied thefe mixtures, fhewed that thefe fubftances re-acted confiderably on each other, and confequently might be intimately combined. ; Thefe phenomena, and particularly the eafy production of marine ether, by the fmoaking fpirit of Libavius, prove that the marine acid which has been combined with metallic fubftances, is in the fitteft ftate for its intimate combination with fpirit of wine, and for the formation of an ether. Does it acquire this property, by depofiting along with the metals a portion of fome of its principles 3 for inftance, of its mercurial earth ; or by carrying off fome of the principles of the metals? To me the latter feems certainly the method ; and that the metallic principle which it carries off is the phlogifton of the metals. The beft means of deciding this interefting queftion, is to com- bine the acid with feveral metallic fubftances, particularly with thofe which contain much phlogifton and eafily part with it, as zihc, regulus of antimony, tin, and iron, and then to feparate the acid from thefe fubftances; not onl to try whether ether can be made by the acid thus prepared, but alfo to afcertain by the other means which chemiftry affords, whether the acid be really by this method combined with a portion of the phlogifton of the metals. Mr. Pott, as well as Stahl, affirms a fact which confirms thefe notions, and which well deferves to be afcertained ; which is, that the properties of the nitrous acid may be given to the marine by combining the latter with iron. (mz) But itis very cer- tain, that the principal difference betwixt thefe two acids proceeds from the quantity of phlogifton which enters as a principle into the compofition of the nitrous. See ETHER (MARINE). The affinities of marine acid, according to Mr. Geof- froy’s Table, are in the following order: tin, regulus of antimony, copper, filver, mercury. According to Mr. (m) This fa& has not been afcertained by fome later chemifls, the Duke D’Ayen, and M. Machy, who, led by the authority of Stahl, have in vain attempted to tranfmute the marine acid into the nitrous. Neverthelefs, Dr. Prieftley relates that Mr. Woulfe, a very able chemift, has effected the change of the marine into the nitrous acid, and alfo of the nitrous into the marine. £x- periments and Obfervations on Airy Vol. 11. p. 1061. - Gellert, PT SE a a pnt ‘not di A C1D Gellert, its affinities are placed thus: phlogifton, zinc, iron, copper, tin, lead, bifmuth, regulus of antimony, Tercusls arfenic. This Table fhews alfo that it does olve gold, and partly diffolves filver by the dry method. (7) ACIDS (MINERAL). Mineral acids are thofe which are obtained from minerals, or fubftances dug from the earth ; fuch as fulphur, bitumens, alum, [elenites, vitriols, clays, all which contain witriolic acid; the nitrous earths, () The affinity of tin is greater than that of copper to marine acid, according to Mr. Geoffroy’s Table, and lefs, according to Mr. Gellert’s Table. I have obferved that tin readily precipi- tates copper from this acid, and alfo from aqua regia: Mr. Gellert is therefore miftaken. The affinities of this, and alfo of other acids to metals, vary in different circumftances. Thus, for inftance, although marine acid unites generally with copper or wich iron, preferable to mercury, or regulus of antimony; yet if either of thefe latter metallic fubftances be added to a mixture of fea-falt and vitriol, green or blue, and confiderable heat applied, the marine acid of the fea-falt, difengaged from its bafis by the acid of the vitriol, will not unite with the iron or copper of the vitriol, but with the mercury or regulus of antimony, and along with them will be raifed by the force of the fire, forming mercury {ublimate, or butter of antimony. Mr. Hellot found, that by repeatedly drying and diftilling the mother water of fea-falt, more and more marine acid could be obtained without addition. Marine acid renders calcareous earths and metals foluble in Apirit of wine; but it does not render volatile alkali foluble in {pirit of wine, as nitrous acid does; nor fixed alkali, as ace- tous acid does. Marine acid, together with burning phlogifton, gives a red- difh yellow flame. The marine acid of mercury corrofive {ub- limate, combined with copper, forms a fufible mafs, which kindles like fulphur, and burns with a blue flame. The phof- phorus of Homberg, which is a combination of the marine acid of {al ammoniac with calcareous earth, to which a portion of the inflammable principle of the fal ammoniac adheres, is luminous when ftruck in the dark. From thefe falts, together with the preparation of marine ether, we may perceive that marine acid is capable of uniting with phlegifton, and that a marine ful- phar might probably be formed, if the volatility of marine acid did not prevent the application of heat fufficient for the forming of that combination. Homberg found, that marine acid corrodes glafs more than the vitriolic or nitrous acids. For the procefs of obtaining marine acid, fee SPIRIT of SALT. from AC1D from which nitrous acid is obtained ; antl Sal-gem, fea-falt, or common falt, which furnifh marine acid. There are then three mineral acids, the vitriolic, nitrous, and marine. Thefe acids are generally more fimple, lefs volatile, more fufceptible of concentration, and ftronger than the acids obtained from animals or vegetables. Hence their power of decompofing all the neutral falts whofe acids are of the latter kind, of difengaging thefe acids, and of fubftituting themfelves in their place by uniting with the {ubftance, which together with the animal or vegetable acid had formed the neutral falt. See Acip, Aci (Vi- rriovic), Acip (Nrrrous), Acip (MARINE). ACID (NITROUS). Nitrous acid has all the general properties of faline acid fubftances, mentioned under the article Vitriolic Acid. See Acip (ViTrioLic). But it differs from vitriolic acid in the following circumftances: 1. It is lighter than the vitriolic. The weight of the moft concentrated nitrous acid, which can be obtained by ordinary means, is to the weight of water as 19 to 12. See a memoir of Mr. Rouelle concerning the inflammation of oils, in the Memoirs of the Academy for the year 1747. 2. It is of a yellowith-red flame color. 3. It is lefs fixed than vitriolic acid, and cannot there- fore be ever obtained in a concrete form, when unmixed. 4. It perpetually exhales in vapours of the fame color as itfelf. 5. Its fmell and tafte are peculiar and diftinguifhing. 6. When highly concentrated, it Reon oars the moifture of the air, but lefs ftrongly than “vitriolic acid highly concentrated. | 7. ‘When concentrated nitrous acid is mixed with water, a confiderable heat and ebullition are produced from the ativity with which thefe two fubftances combine. While they are mixing, a fingular and curious phenomenon appears, which is, that the liquor affumes a blue or deep green color, while the vapors continue ftill of their original yellowith red. M. Beaumé has made this obfervatjon. ‘This blue color, as the fame chemift has remarked, dif- appears in a few days, if the nitrous acid has been diluted with much water. Concentrated nitrous acid is very corrofive. It tingesthe fkin with a yellow color, which does not difappear till the epidermis comes off. It is fuccefsfully employed to corrode and gradually deftroy warts, and uninflamed, in- dolent tumors. If — og A EO ———————————— a ee ail ACID in If the opinion of Becker, Stahl, Junker, and all thé ~fcholars of Stahl be true, that there is only one primitive acid, whence the reft are formed ; and that this moft imple acid, the principle of all others; is the vitriolic, then it follows that nitrous acid is nothing elfe than vitriolic acid, changed by the union of fome other principle. Further; thefe ch¢mifts think that nitrous acid is formed from the vitriolic, combined, by means of the putrid fermentation, with a certain quantity of phlogifton: To prove their opinion, they give the following reafons : 1. That the nitrous acid is obtained from nothing elfe than materials impregnated with putrid juices of animal and vegetable fubftances, which afe known to abound with phlogifton : whereas vitriolic acid exifts in moft minerals, and in the very earths and ftones, which are fitteft to form a matrix for the generation of nitrous acid. La, 2. There is a great analogy betwixt thofe properties of the nitrous and volatile vitriolic acids, by which each of thefe acids differs from vitriolic acid; and volatile vitriolic acid is evidently vitriolic acid changed by union with phlogifton. , This volatile vitriolic acid differs from vitriolic acid by its valatlies, by its fmell, by its weaker adhefion to alka- line falts, by the greater folubility and different form of the cryftals refulting from its union with alkaline falts. But thefe properties are the fame which diftinguith nitrous acid from the vitriolic. ~Befides, the volatile vitriolic and nitrous acids refemble each other, and differ from vitriolic acid in the following refpects : 1. They pro- duce a much greater alteration on the colors of vegetables than the vitriolic does : and, 2. The falts formed by their combination with fixed alkali refemble each other, and are equally different from vitriolated tartar; Several new interefting experiments might be made to determine more particularly the analogy betwixt the vola- tile vitriolic and nitrous acids, The falt refulting from the combination of volatile vitriolic acid and abforbent earths might be examined, in order to difcover whether it be deliquefcent, like the falt from the combination of the fame earth with nitrous acid, and in what other circum= ftances thefe two falts refemble each other, and differ from the vitriolic falt with earthy bafe, or. felenites. This inquiry would be ftill more interefting, as the nitrous falts with earthy bafes have alfo been little examined. Ses SaLts (NITROUS) with EARTHY BASES 3 Nitrous ‘poflible ; or when it can, in the ve A C1D Nittous acid is one of the moft powerful menftruums in chemiftry : not that it is the firongeft acid ; for in ftrength it is inferior to vitriolic acid, and even in certain circum- - ftances to marine acid : but on account of the facility, of the quicknefs, and of the aétivity with which it diffolves molt Japleness, e- bodies upon which it ats moft forcibly are - gifton, alkalis fixed and volatile, metallic fend he earths, particularly of the calcareous and abforbent kinds. Nothing can equal the impetuofity with which nitrous acid joins itfelf to phlogifton. It is fo great, that probably nitrous acid has a ftronger affinity with phlogifton than the vitriolic has: and it is probable too, that this proczeds sre the phlogifton being one of the principles of nitrous acid. The phenomena exhibited by nitrous acid with all matters containing phlogifton, are different according to the ftate of thefe matters, and of the acid itfelf, | When the phlogifton of the fubftances applied to nitrous acid is in fmall quantity, and inveloped in much unin- flammable matter, and when the nitrous acid is diluted in much water, from which it cannot difengage itfelf in the act of combination, then it diffolves thefe fubftances always with more facility, quicknefs, and a&ivity than the other acids, all circumftances being fuppofed alike; but it dif folves them without being itfelf decompofed, and forms alon with them new combinations. But when the fubflerrs to which the nitrous acid is applied, contain much phlo- gifton, as fulphur, oils, charcoal, and many metallic matters; and when the nitrous acid is dephlegmated as much as is act of combi become dry, and receive at the fame infant the wi of eat” tion, whether this heat be applied to it, or it be generated by the violence of the re-adtiop ; then does the nitrous acid in this ftate of heat and drynefs, combine intimately with the phlogifton, and form with it a kind of fulphur or nitrous phofphorus, which is inftantaneoufly inflamed and decompofed in fuch a manner, that not only the phlogifton, but alfo the nitrous acid itfelf, is entirely burnt and eftroyed. And “this combuftion is effected Gandy from all others, with- out the neceffity of accefs of air. ( ence the inflammation the detonations, the explofions, - which always happen when all thefe circumftances concur. See DeToNATION 2/ N1TRE with fulphur, &c. GUNPOWDER, FULMINATING OWDER, Rena GoLp, INFLAMMATION of Ors. LL | C Nitrqus = 3 : a: ’ . EE — I~ A C1HD . Nitrous acid forms with fixed vegetable alkali a neutral cryftallizable falt, called mitre, or Jfalt-petre. See NITRE. With marine or foflile alkali it forms a cryftallizable falt, called cubic, or quadrangular nitre, from the figure of the cayftals. See NiTRE (CUBIC). With volatile alkali it forms a neutral falt, capable of cryftallizing, called ammoniacal nitre, or nitrous [al ammoniac. This falt has the property of detonating without addition of phlogifton, becaufe phlogifton is contained in the volatile alkali. See Ammoniac (NiTROUS). Nitrous acid diffolves with much facility and readinefs all calcareous and abforbent earths, and forms with them neutral , falts not capable of cryftallization ; undoubtedly becaufe of the {mall adhefion of this acid with the earths. Thefe falts, when dryed and expofed to the air, deliquiate or melt into a liquor. They are called nitre with earthy bafe, or nitrous [felenates. The a&ion of nitre upon other earths is not yet well known. . See NITRE with EARTHY BAsis. Nitrous acid attacks and diffolves in general all metallic {ubftances, gold and platina excepted, which it alfo dif- {olves when it is united with marine acid ; and the marine acid is likewife incapable of diffolving thefe metals without the affiftance of nitrous acid. i The. phenomena prefented by nitrous acid in metallic folutions are very numerous. The particulars may be feen under the articles of each metal. We fhall only here make fome general obfervations upon this fubject. 1. Nitrous acid, in diffolving metallic fubftances, emits a great quantity of red vapors; and ceteris paribus, pro- duces more heat than when it diffolves alkaline falts or earths ; which can only be attributed to the phlogifton of metallic fubftances. 2. There are metallic fubftances with which nitrous acid forms falts capable of cryftallization and detonation. Such are particularly filver, lead, mercury, and bifmuth, With mofl other metals, as with copper, tin, iron, and regulus of antimony, it forms deliquefcent metallic falts, which partly are decompofed fpontaneoufly by the feparation of the metallic part. This difference proceeds from the greater or lefs quantity of phlogifton, which the nitrous acid takes from the metals in folution. Thofe metals from which ‘it takes little phlogifton, form with it more intimate com- “binations, becaufe they retain a good deal of that principle ‘which is the medium of union betwixt their earth apd the acid. ACID acid. ‘On the contrary, the folution of the metals from, which this acid takes much phlogifton, is attended with much more ebullition and violence: and when the acid is ftrong, when the quantities of the acid and metal are large, and the metal reduced to filings or grains, then the heat, the ebullition, and the exhalation of vapors are car- ried to their higheft point, almoft to inflammation. It is even probable that a real inflammation might be produced if the experiment were pufhed far enough. : A remarkable phenomenon, which has not been attended to, is, that the metals from which nitrous acid takes leaft phlogifton, are thofe which form with it the moft corrofive falts; fo that mercurial nitre and the nitre of lead are true poifons. This remark may help to explain the corrofive quality, or caufticity, which the combinations of the mi- neral acids with metallic fubftances generally have. See CavusriciTyY. Nitrous acid is eafily combined with all oils, and with all oily and inflammable matters. It acts upon thefe matters more {lowly and weakly, in proportion as it is more diluted with water. It thickens them, and forms with them refinous or faponaceous compounds, according to their nature and the proportion of the acid. When the acid is very concentrated, it burns and inflames them. See IN- FLAMMATION of Oils. It eafily unites, even when much diluted with water with fpirit of wine. It combines intimately with that fub- ftance, and thereby lofes much of its acidity. It is then called [pirit of nitre dulcified ; which fee. With proper proportions and management, it changes part of the fpirit of wine into a liquor which has the prin- cipal properties of vitriolic ether. Sec ETHER (NITROUS). The affinities of nitrous acid are, according to Mr Geoffroy’s Table, iron, copper, lead, mercury, filver : and according to Mr. Gellert, phlogifton, zinc, iron, regulus of cobalt, copper, bifmuth, lead, mercury, regulus of anti- mony, filver, arfenic, and tin. The tin is there faid to be only partly foluble, undoubtedly becaufe of the abundant iin of hs WA of the tin, which the nitrous acid rives of its phlogifton, and i ‘ci Se 2 bd loghhivay : nl in fome fort calcines rather C2 ACID (¢) Nitrous acid forms with co + with i nl oN pper, a green ; with iron, a red- dith ; with lead, a yellow ; and wich filver, bifmuth, mercury, and ER RR ROR RN OCR CORR — I. - . ACID ACID (PHOSPHORIC). Se PuospHoRUS. ACID (VOLATILE SULPHUREOUS), or (VorartiLe Virrioric). This is nothing elfe than vi- triolic acid diluted with water, and weakly united to the inflammable principle. The- properties of this acid are then the fame ¢/fentially as thofe of vitriolic acid. See AciD (ViTrioric). But the phlogifton which is united with the volatile acid makes it differ confiderably from the pure vitriolic acid. ) It differs from vitriolic acid, 1. By its fmell, which is fo active and penetrating, that it can inftantaneoufly fuffocate and kill animals. ‘This fmell is the fame as that of lighted fulphur. As vitriolic acid, when pure and free from phlo- gifton, has no fmell, it appears that the fmell of volatile vitriolic acid is caufed by its phlogifton; and this is one of the beft proofs of the opinion of Stahl and other che- mifts, who think that phlogifton is the principle of all odors. This opinion will appear even demonftrated, when we confider that no odoriferous fubftance can be found, in which it is not eafy to fhew the prefence of phlogifton. See PHLOGISTON. 2. The volatile acid differs from the vitriolic by its ve- latility. The latter is the moft fixed of the mineral acids, and is for that reafon the moft fufceptible of concentration : but the volatility of the former is fo great, that it cannot be much concentrated. This property proves that phlogif- ton is a principle effentially volatile. 3. The volatile acid is infinitely weaker than vitriolic acid ; not only becaufe it cannot be fo much concentrated, but alfo by its combination with phlogifton it is rendered lefs fimple, and confequently lefs capable of affinity with and zinc, colorlefs folutions. Tin it diffolves imperfe&ly, and it - corrodes regulus of antimony to a white powder. With regulus of cobalt it forms a red, and with nickel a green folution. It diffelves arfenic, and, according to Henckel and Neuman, forms with it a gum-like fubftance. Dr. Brandt found that by particular management it can diflolve gold. See Gonp, It has little effect on metallic calxes. Nitrous 2cid combined with chalk forms the phofphorus of Baldwin. Sec Prosproric Stones. Cohobated and diftilled. | with quicklime, it emitted an inflammable vapor. See Mr. Pott’s Differtation on the Solution of Quicklime by Nitrous Acid. With ice this acid produces cold remarkably. Concerning the origin of nitrous acid, fee NiTrE and Sart; and for the procefs of ob- taining it, fee Se1riT of NITRE. | other a C1:P other bodies. Therefore, the neutral falts formed by it with alkalis, -are eafily decompofed by vitriolic acid, and alfo by all other acids, even the weakeft amongft the vege- table. : Hr The neutral falt which refults from the union of volatile vitriolic acid and fixed alkali, differs much from vitriolated tartar with refpet to the figure of its cryftals, which are long and needle-like, arranging themfelves to- gether in form of tufts or fhrubs. Its tafte alfo is different from that of vitriolated tartar, and it is more foluble in water : all thefe properties thew in a neutral falt the weak union of its acid and bafe. This falt is called the fulphu- reous falt of STAHL. See SALT (SULPHUREOUS). 5. "The action of the volatile vitriolic acid is much more evident than of vitriolic acid upon the colors of vegetables, as appears by pouring an equal quantity of each of the two acids into the tin&ure of violets, or of heliotrope, of coche- nille, Brafil wood, &c. In all thefe inftances, the tinctures into which volatile vitriolic acid has been poured, will have loft much more of the intenfity of their colors than the other tin&tures; that is to fay, their colors will be more changed, enlivened, and heightened. This effe&t is pro- ane to fuch a degree by this acid, that it deftroys moft colors, and makes them difappear entirely in time. This property renders it very ufeful in feveral arts, by giving to certain matters, for inftance to wools and filks, a degree of whitenefs to which they could not be otherwife brought. For this purpofe, thefe matters are expofed in a clofe place to the fumes of burning fulphur, from which, as we fhall afterwards fee, much of this acid exhales, Sec SuLPHUR. Although volatile vitriolic acid differs eflentially from nitrous acid, fince the former is nothing elfe than vitriolic acid difguifed by the addition of phlogifton, which is but weakly united to it; neverthelefs, it is neceflary to remark, that all the properties now recited of the volatile acid, make it refemble nitrous acid as much as they diftinguith it from vitriolic acid. From this remark may % drawn one of the ftrongeft prefumptions in favor of Stahl’s opinion concern- ing the nature of nitrous acid. This great chemift thinks, that vitriolic acid, which he therefore calls the univerfal acid, is the principle of all other acids, and the moft fimple of all. He thinks that nitrous acid particularly is nothing elfe than vitriolic acid combined by means of putrefaltion with a certain quantity of phlogifton; but in a manner very dif- ferent, and ipfinitely more intimately than the phlogifton is 3 combined EAR Hohe ACID combined ‘in volatile vitriolic acid. For this latter com- bination is fo weak, that it is decompofed by contaét of air; fo that the moft ftrong and penetrating volatile. vitriolic acid, by expofure in open veflels, lofes in a little time all its {fmell and volatility, and becomes entirely fimilar to a pure and weak vitriolic acid. ‘The fame phenomenon takes place when the volatile acid is combined with an alkali. Hence the fulphureous falt of Stahl, expofed for a while to free air, lofes all the properties which diftinguith it from vitriolated tartar, and becomes no-wife different from it. The true reafon of the weaknefs of adhefion of the phlo- gifton in volatile vitriolic acid, is the prefence of the aqueous principle, above the quantity of water eflential to vitriolic acid. This principle always refifts a ftrong. and intimate union of phlogiften with an body. This is fo true, that if vitriolic acid deprived of all water except what is eflential to it, be applied to any matter con- taining phlogifton, volatile vitriolic acid is not then pro- duced, but true fulphur, in which the phlogifton adheres more ftrongly. See SuLpHUR. On the contrary, ‘when a vitriolic acid, overcharged with {uperfluous water, is com- bined with a matter containing phlogifton, volatile vitriolic acid is conftantly produced, and never fulphur, except that in the very a of combination the vitriolic acid he deprived of all its estan water. The great facility which vitriolic acid has to combine with phlogifton, even when fuperfluous water is mixed with it, furnithes many methods of producing abundantly this volatile vitriolic acid. Stahl propofcs two. The firft is, by burning fulphur as flowly and gently as poffible. ‘The acid which exhales in this operation is very volatile, very phlogifticated, and very fuffocating ; for two reafons: 1. Becaufe of the little activity with which the fulphur burns, the inflammable principle is not entirely confumed, but a portion. of it remains united to the acid: and, 2. Becaufe when the vitriolic acid, which in fulphur is in its higheft degree of concentration, and even in a ftate of perfect drynefs, difen- gages itfelf by degrees, during the flow burning of the fulphur; it finds in the air a portion of water which jt greedily feizes, and which renders it fit to be changed with the remaining phlogifton into volatile vitriolic acid. When fulphur is burnt haftily and frongly, little or no volatile vitriolic acid is produced, principal y becaufe then almoit all the A C1D ¢he inflammable principle of the fulphur is deftroyed by this hs el obtaining the volatile vitriolic acid is obi od eafieft, when it is not intended to collet it, Jot the f it to fome body as foon as it 1s produced ; as, 3 . oh to kill infeéts or noxious animals, to Wiis Gon eS Hite to fulphurate wines, or to produce the vy ie an Galt of Stahl, ‘See Sart (SULPHUREOUS). fos 2 io wk But this method is improper for col eins ke acid, becaufe fulphur cannot burn in clofe pi Stahl for obtaining the ] d method propofed by Sta btaining t| hd Ne riolic acid, is by diftilling green or martial on in TE retort, to which a receiver 1s prope ; By this method 2 gorfiferants : quently 3 produce a ; ufe, 1. The phlegm of the | of Sol op water to “the vitriolic wl ny " ? nough of the phlogifton- of Ay an ik Wn ve crack of the veflel, to form volatile olic Sh ae nol, though very good in itfelf, pe " a ver great inconveniency in practice; hin is, at when be retorts are expofed 3 LPR with © great “© : : ion, they are very apt to break {till more, to fall in es by which ft re s ring vy is inconveniency may be avoided by ciiulling a), a Y dictate of viral acid, or — taining it, and any matter capable oO aint at wl rer ad phlogifton. Fl i wi of > ne oils, . mixed and diftilled with vitriolic acid, can ear Tort gd anit of ‘ftrong volatile vitriolic acid. See O1L and ETnER (VITRIOLIC). AY This acid ought te be kept in gan eset) a 8 a a i 3 be as little as pofii : | with glafs ftoppers ; and to oie enpeled i rs always exhale from it when fo e potted, by which ts firength is impaired from the diffipation ’ 4 ; f its phlogifton. oe great faciity which the giogiten ing 2 operas i m volatile vitriolic acid, is the caufe of eed- el ity re even impoffibility of determining precifely ns quantity of phlogifton necellry. 3 Sones weg Give i itriolic acid into volatile vitriolic . pm o a that very little is required ; a fingle grep of oil being capable of converting, by Sites, 2 arge quantity of vitriolic acid ne Yery {trong volatile acid. I A C1D It is no lefs difficult to determine certainly and precifel the properties of this acid as a menftruum of different fub- ftances ; as, for example, earths and metals. This difficul- ty alfo proceeds from the facility with which it parts with its phlogifton, and confequently changes its nature, which it does more or lefs in the a&t of combination with the fub-, ftances which it diffolves. It is an acid perpetually chang- ing, and which we cannot be certain of having the fame at different times. Thefe difficulties ought not to prevent trials of fuch com- binations, hitherto little known. Becaufe in an important and cflential enquiry, which may throw new light upon the theory of acids and phlogifton, even approximations become: important and eflential. ACID (TARTAREOUS). Se TarTAR, and Cream of TARTAR. ACIDS (VEGETABLE). All acids obtained from vegetable matters are fo called. Such are the juices of four fruits, wine turned four, or vinegar ; cryftals of tartar; all the eflential, acid, concrete falts, procured by cryftalliza- tion from the exprefled juices of plants; and laftly, all the acids obtained from vegetable fubftances in analyfing them by diftillation. Thefe acids differ from mineral acids in being lefs fimple, Yefs fixed, lefs fufceptible of concentration, and weaker ; qualities, which proceed from their union with a certain quantity of oil, with which they are fo intimately com- bined, that they cannot be feparated from it but d very nice and ftudied operations. Hence all the neirer falts formed by thefe acids may be decompofed, either by the mere action of the fire, or by any mineral acid whatever. The particulars of what is here advanced in general on their properties and principles, may be feen under the ar- ticles of the principal vegetable acids. ACID (VITRIOLIC) was fo named, becaufe, for- merly, it was chiefly obtained from martial vitriol. It is, according to the very probable opinion of Becker and of Stahl, the fimpleft of all acids, and confequently the fim- pleft of zl! faline fubftances. When it is as pure as can be obtained, it is entirely free from {mell and color ; that is to fay, in thefe refpelts, it refembles water. It poliefles moft eminentlyall the properties charaerifing faline, and particularly acid fubftances. It taftes exceedingly four, and it fets the teeth on edge. ACID It changes to red the color of fyrup of violets, of tinc- ture of heliotropium, &c. A It is very fufceptible of concentration; that is, much of the water unneceflary to its faline eflence may be raifed by diftillation. See CONCENTRATION. The fpecific gravity of this acid, when much concen- trated, is very great. It is more than double the fpecific ravity of water, fometimes as 17 to 8, and perhaps might Be further concentrated. M. Hellot, in pufhing ftrongly the diftillation of martial vitriol, obtained towards the end of the operation a vitriolic acid fo concentrated, that it was folid and cryftalline. Some chemifts have given to vitriolic acid 16 concentrated as to become concrete, the name of GraciaL, or Icy OIL of ViTRIOL. : Vitriolic acid highly concentrated is lefs fluid than water. It pours ropey like oil, and feels to the fingers greafy. Thefe two a roperties have occafioned the ancient che- mifts to call it Oil of Vitriol. ‘This name is very improper, {ince it is not inflammable, nor has any peculiar properties of oils. See O1Ls. Its oily confiftence is owing to the great approximation of its parts, and its apparent unctuofity pro- ceeds from the fame caufe; joined to this, that as it is a very powerful diffolvent, it attacks and diffolves effectually a portion of the unctuous fubftance of the fkin which it touches. The very ftrong and concentrated vitriolic acid is not only much heavier, but alfo much more fixed than water. Hence it is capable of receiving, when expofed to fire, 2 degree of heat greatly fuperior to that of boiling water, and which almoft amounts to a red heat. This acid, when well concentrated, (which we fuppofe bere all along) unites with water with an aftonithing activity and impetuofity. If two or three ounces of it be mixed with as much pure and cold water, the re-ation of thefe two fubftances on each other is fo ftrong, that inftantly a boiling arifes, attended with many vapors, and a noife fimilar to that of red-hot iron plunged into water. ‘The heat refult- ing from the re-altion of thefe two cold liquors is fo great, that in an inflant it equals, and even much furpafles the Beat of boiling water. Some chemifts have at:ributed this heat to a difengagement of the igneous particles contained in vitriolic acid. "This is not true, except they only mean the igneous particles contained in this acid, as in all other fubftances, and which are fet in motion by all collifions ; but ACID but not any fuperabundant igneous particles peculiar to this acid, fince no experiment demonfirates their exiftence. "The concentrated vitrolic acid, expofed to the atmofphere, attradts moifture fo much, that its bulk is confiderably en- creafed, and it becomes mixed with twice its weight of wa- ar. ot 4 It { be combined with the inflammable principle or phlogifton, and thereby form two compounds, differing from each other in the quantity of phlogifton, and in the clofenefs of the union. or 0 The fir, which is the refult of a combination of weak vitriolic acid with a {mall Quariiey of phlogifton, is called volatjle fulphureous acid, or volati e vitriolic acid. See ACID (SULPHUREOUS) ; and the fecond, which arifes from an intimate union of vitriolic acid, freed from all water above what is neceflary to its eflence asa faline fubftance, with about a feventh part of its weight of pure phlogifton, is called Sulphur, See SULPHUR. Ng Vii Earths are more or lefs foluble by vitriolic acid, accord- ing to their natures; and form with it different falts, or carthy faline compounds of different properties, according to the kinds of earth employed. Particular management 1s requifite to combine vitrifiable earths with vitriolic acid : ond the falts refulting from their combination have not yet been fufficiently examined. See ViTRIFIABLE EARTHS and uOR of FLINTS. ] Le earths may be diffolved without any previous preparation by vitriolic acid. This folution 1s made with moderate effervefcence 3 and from this combination refults an carthy fzline compound, fufceptible of cryftallization, whofe principles are fo intimately combined, that the falins properties of the vitriolic acid are almoft entirely hid an covered by thofe of the earth which is the prevailing prin- ciple (fee AFFINITY); fo that this neutral vitriolic falt with (yp) Dr. Gould relates, that three drams of concentrated vitrio- lic acid acquired by imbibing moifture from the air, 1n 57 days, an in-reafe of fix drams and a half ; and that in general this aci acquires increafe of weight in a compound ratio of the largenes of ‘the furface expofed, and of the humidity of the atmofphere. Neuman found that an ounce of this acid, by expofure to air duiing a year, had imbibed more moilfture than fix times 1ts ori- ginal weight. For the method of obtaining tals acid, fee SPIRIT "SULPHUR, CrLyssus of SULPHUR, and CONCENTRATION of YiTriovic AcCiD. earthy A C1D earthy bafis has no fenfible tafte, and is fcarcely foluble in water : according to Mr. Baumé’s experiment, one grain only of it could be diffolved in an ounce of water. This want of faline properties, which appears common to all vi- eriolic falts with bafes of calcareous earth, has eccafioned them to be diftinguithed by the name of Selenites, from other combinations whofe faline properties are more obvious. Sec SELENITES. Alum is a vitriolic falt with earthy bafis, but it differs confiderably from Selenites. This difference proceeds from the nature of its earthy bafis, which is not calcarcous, but argillaccous. See ALUM. Vitriolic acid may be combined and faturated with vege- table fixed alkali: and from this combination is formed a neutral falt, capable of being cryftallized, bitter, hard, and not eafily foluble in water. Several names were given to this falt from the feveral fubftances whence its alkaline bafis was extralted, ata time when thefe alkalies were fup- pofed to differ from each other, Thefe names are, Sal de duobus; vitridated tartar; arcanym duplicatum. See thefe wards, and ALKALI (VEGETABLE). With the alkaline bafis of fea falt, called marine or foflile alkali, the vitriolic acid forms a neutral, cryftallizable falt, called Glauber’s falt, which differs from vitriolated tartar in the figure of its cryflals, its greater folubility in water, the quantity of water contained in its cryftals, and its property of drying in the air, or lofing much of its water, by which the cryftals lofe their tranfparency, their folidity, and are reduced into a white meal, called efflorefecence. See ALKALI (MARINE), and SALT of GLAUBER. Volatile 2llzali combined to the point of faturation with 2 vitriolic acid, forms a neutral ammoniacal falt, and cryftal- lizable, called Salt (Vitriolic Ammoniac), which fee, and AL~ KALI (VOLATILE). Vitriolic acid being more fimple and more powerful than the nitrous and marine acids, feparates them from the alka- lis to which they are united, and fubftitutes itfclf in their place. See NivrE and SALT (CoMMON). In general, this acid alls upon all metallic fubftances, and dificlves them with phenomena peculiar to each. It forms with them neutral {alts with metallic bafes capable of cryftallizing ; to all which falts M. Macquer thinks pro- per in his Courfe of Chemiftry to give the general name of vitrial, and to {pecify the different vitriols by the name of the metallic matters which enter into their compofition. Thus, i a——r— — A C1D Thus, for example, he propofes to call the combination of vitriolic acid with filver, witriol of filvery or lunar vitriol 3 and the combination of the fame acid with mercury, vi- triol of Mercury, 8c. in the fame manner as the neutral me- tallic falts formed by the union of vitriolic acid with iron, and with copper, are called vitriol of copper, and vitriol of iron, or martial vitriol. See VITRIOL. This acid, in confequence of its great affinity with the inflammable principle, attacks the phlogifton “of metals when it diffolves them, and feparates part of it from thofe which are capable of being deprived of it; confequently it calcines them more or lefs according to their nature, and to the manner of making the folution, and adheres to them proportionably lefs, as it has taken from them a greater quantity of their phlogifton. We may conclude from thefe phenomena, that vitriolic acid diffolves metals, chiefly by means of their phlogifton ; or that this principle is a me- dium of union between this acid and metallic earths. ‘The moft general phenomena accompanying the folutions of metallic matters in vitriolic acid by the humid method, are, 1. The effervefcence and heat, which are commonly moderate. 2. The vapors; many of which are the vola- tile vitriolic acid, as in the {olution of mercury; or they are inflammable vapors, as in the {olution of iron. 3. The formation of concrete fulphur, as in the folution of tin. See the particular details A all the folutions of metallic matters by witriolic acid, under the article of each metallic [fubftance, and at the word VITRIOL, (q) . t (¢) Diluted vitriolic acid diffolves iron and zine fpeedily, and copper very {lowly. Boiling concentrated vitriolic acid diffolves copper, and partly diffolves and partly corrodes filver, tin, mer- cury, and lead. Vitriolic acid does not diffolve gold, but preci- pitates it from aqua regia. It leffens the volatility of mercury and of arfenic; and the fufibility of lead, zinc, bi{fmuth, and regulus of antimony, when combined with thefe metallic fub- fiances. It diffolves the calxes of moft metals. It alfo diffolves the regulus of cobalt, but not nickel, i Although vitriolic acid has a ftrong power to combine with iron, yet itsadhefion to it when diffolved feems to be very weak. Thus Mr. Margraaf found, that by boiling 2 folution of green vitriol in a copper veflel, or with filings of copper, part of the jron was depofited, and in its place part of the copper was dif- folved. This experiment is fo much more remarkable, as a di- luted vitriolic acid has no fenfible effet upon copper in a fhort time. AC1D It appears from what has been faid on the combinations of vitriolic acid with all the fubftances with which it can form a neutral falt, that all thefe neutral vitriolic falts are fufceptible of cryftallization. This property is peculiar to vitriolic acid, and probably proceeds from the intimacy of union contracted betwixt this acid and the fubftances which it diffolves. Concentrated vitriolic acid a&s with confiderable force "on oils and concrete oily matters. It boils and grows warm when added to them. it partly decompofes them, blackens, and in fome fort’burns them. From thefe mixtures many fumes exhale, which have a mixed fmell of burnt oil, and of very fuffocating volatile vitriolic acid. See the detail and explanation of the phenomena at the word OIL. Vitriolic acid, when very weak, docs not appear to have any action upon oils, becaufe its fuperfluous water, with which it ftrongly adheres, hinders it from combining with thefe fubftances, to which the water cannot be united. However, the union of fuch a weak vitriolic acid with oil, does not feem impoffible. See O1L. The mixture of concentrated vitriolic acid with fpirit of wine, fhews many very interefting phenomena, which vary according to the proportions of thefe two acids, and the management employed. Without diftillation, it entirely combines in {ubftance with fpirit of wine, without occafioning any decompofition that is to fay, it does not combine with any of the principles of the fpirit of wine preferably to the reft. It lofes its acidity by this union, and is rendered greatly milder. Hence time. The acid therefore by its previous folution of iron feems to have been fo changed, as to be rendered capable of diffolving copper. This experiment does not contradiét the general tule by which the power of union of vitriolic acid is affirmed to be greater. to iron than to copper, but may be explained from the flight ad- hefion of the inflammable principle to the earth of iron ; by which property, falts formed by this metal with vitriolic or ni- trous acids are continually decompofing ; the phlogifton of iron, efcaping into the air or combining with the acid, and its calx feparating from the acid, in form of a red fediment. This de- compofition of martial vitriol, and martial nitre, and allo of fome other metallic falts fubjeé to the fame change, is accelerated by application of heat, air, moifture, and, as Mr. Margraaf’s experiment feems to indicate, by the application of another metal, as copper. ; it A € IB it is called Dulcified Vitrislic Acid. It has alfo been called WATER of RasEL ; which fe. - When fpirit of wine and vitriolic acid are diftilled toge= ther, the latter decompofes the former, takes pofleffion of its aqueous principle, reduces a part of it into a middle fubftance betwixt ardent fpirits and oil, to which the name Ether has been given; and laftly, the acid reduces the {pirit of wine into a true oil, which has been improperly call- ed Sweet Oil of Vitriol. See the words SPIRIT (ARDENT); Etuer; ETner (ViTrIOLIC) ; and SwERT OIL of Vi- TRIOL. Vitriolic acid is no where in nature found pure; that is, unmixed with any other matter. This proceeds from its capacity to diflolve, and to combine with a great variety of different fubftances. Thus vitriolic acid is found naturally combined, 1. With an inflammable fubftance ; then it is in form of fulphur or bitumen ; or, 2. With earthy fubftances, in form of fe- lenites, aluminous and argillaceous matters ; or, 3. With metallic fubftances, in form of native vitriols ; or, 4. With alkaline falts, in form of neutral vitriolic falts, with alka- line bafes. But it is almoft only with the foffile or mariné alkali that the vitriolic acid is ever found naturally combin- ed, becaufe this alkali is moft generally diffufed, ‘and is in= deed almoft the only native alkali. Vitriolic acid is there- fore found in form of Glauber’s falt. Glauber’s falt is chiefly found in thofe waters which contain common falt. See Sart (Common), and WATERs of Sart Foun- TAINS. Vitriolic acid, combined with vegetable fixed alkali, forming vitriolated tartar ; or with volatile alkali, forming vitriolic ammoniac falt, otherwife called the fecret ammo- niac falt of Glauber; are found very rarely, and are pro- duced by particular decompofitions and combinaticns ; as, for example, by burnings. From what has been faid concerning the ftates in which vitriolic acid is naturally and habitually found, we may perceive that it cannot be obtained alone and pure without particular artful operations ; that is, by decompofing thofe bodies which contain moft of it, and from which it may be moft eafily procured. Thefe bodies are Sulphur and Vitriols. See thefe words fo the extraction of Vitriolic Acid. Upon confidering the feveral fubftances with which vitrio- lic aeid is found naturally combined, an interefting queftion arifes AC: 19D arifes concerning the original and primitive ftafe of this acid. . For as fulphur is fpread in very large quantities with- in the earth, and as by burning or decompotition, its acid feparated from its phlogifton becomes capable of combina- tion with earthy and metallic fubftances (as happens actu- ally in the fabrication of cvitriols and of alum) ; we may confider whether all vitriolic acid has been originally in the {tate of fulphur ; and a part of this fulphur being confumed or decompofed by natural caufes, as happens in volcanos, its acid has formed all the vitriols and vitriolic falts with earthy bafes, which are found formed in the earth ; or whe- ther, (as we know by the experiment of the artificial com- pofition of fulphur, that vitriolic acid quits every other {ub- ftance in order to combine with phlogifton) all this acid was originally combined with earthy and metallic fubftan- ces ; and thefe vitriolic falts, meeting matters abounding in phlogifton, have been decompofed to form all the {ulphur found in the earth. This queftion cannot certainly be de- cided but by the profoundeft refearches into ‘the natural hiftory of thefe feveral bodies. The affinities of vitriolic acid according to Mr. Geofiroy 5 Table are, phlogifton, fixed alkali, volatile iba earths, iron, copper, and filver : and according to Mr. Gellert’s Table, phlogifton, fixed alkali, volatile alkali, earths, zine, iron, copper, filver, tin, lead, mercury, bifmuth, regulus of antimony, and of arfenic. ACIDS (VOLATILE). Thofe acids are fo called which are more volatile than moft other acids ; which vola- tility proceeds either from an union of fome phlogifton, or of fome attenuated oil. Such are the volatile vitriolic acid; the acid fpirits of fome acrid vegetables, as the roots of fquills, according to Mr. Cartheufer; the acids which rife when butter or fat are diftilled ; and others fimilar. UE. ACIDUM PING rr) Ep (r) Acioum pincue. Frederic Meyer, an Apothecary of Ofnaburg, publifhed in the year 1764, a treatife concerning Quicklime, in which he endeavoured to explain the caufticity of that fubftance, and alfo many other phenomena of chemiltry, by means of a new principle which Le pretended to have dilcovered, and 2 which he has given the name of dcidum pingu-. Dr. Black ha before that time publifhed an account of experiments made upen Quicklime and Magnefia, which proved in the clearelt manner that the caufticity of quicklime, its folubility in water, and its diffolving ADI BE PaT ADEPT is the name affumed by thofe alchemifts who pretended to have difcovered the philofopher’s flone. See STONE (PHILOSOPHER’S). ADOPTER. diffolving power, are original properties of pute uncombined cal- careous earth ; and that the want of thefe properties in lime-ftone, marble, and other native earths capable of being converted by calcination into quicklime, depends on thofe earths being always combined in their native flate with the fluid which has been called fixed air. Neverthelefs, Meyer's theory, in the framing of which more imagination was employed than judgment, and more pains were taken to apply it to the explanation of pheno- mena than to prove its foundation on truth, has been adopted by many, efpecially by German Chemifts, and warmly defended by Crantz, Fourchy, and others. Dr, Black’s do@rine has been very ably defended, and his experiments repeated and confirmed, by Mr. Faquin, in a Treatife called Examen Chemicum dofrine Meyeriana de acide pingui et Blackiane de-aére fixo refpelu calcis FVindobone, 1769. In the following abftra& of Meyer’s doétrine, the readers converfant in modern chemiftry will eafily perceive that he attributes to his acidum pingue, various effefts, fome of which are generally attributed to phlogifton, others to the gas or fluid called fixed air, and laftly, others to the abfence of this fluid, Meyer maintains that the faline capflic quality of quicklime ‘depends upon a peculiar fubftance, which he fuppofes is imbibed by the calcareous earth from the fire during its calcination, To this fubftance he gives the appellation cauflicum et acidum pingue. He thinks that it 1s compofed of an acid, and of the pure principle of fire or matter of light; that itis a fubtle elaftic volatile matter (although it is fixed in quicklime); is analagous to fulphur, and is indeftru&ible. He infers that an acid exifts in this principle : 1. From the folubility of quicklime in water, which he {uppofes can be effetted only by an acid. 2. From the precipitation occafioned in lime-water by adding an alkali, with which he fuppofes that his acid unites, while it leaves the earth. 3. From the change of properties and neutralization which the alkali fuffers by its union with this acid, asthe alkali then ceafes to effervefce. ‘That this acid principle is not a pure acid, he in- fers from its property of uniting with fulphur, oils, and calcareous earths, which fhew that the acid is united with fomething fat or oily. This fat ingredient in his acid principle prevents the acidity of its tafte, and alfo prevents it from forming a neu- tral {alt with alkalis, which, however, are fo far changed by their union with the acidum pin He, that they are rendered foluble in : —— TE CTOT GVreCIan Car ens, oer Ine article fpirit of wine, and EE of ating upon other oily fubftances i NIN SY i : a: cr : ComrosiTioN of Borges, and the following Nose, which they could not unite with in their mild fate, a Vv / ’ D 8 ower The i Vor. I. Pp A TABLE ofr tHE SOLUTIONS oF BODIES, gy Mr. GELLERT. (70.8 placed in Vol. I. facing the article Arriniry. 3 I. 1 Siliceous 2. Fluors 3. Clay 4. Earth Gypfeous Calcareous 5 Earth 6. Fixed Alkali 7 Volatile Alkali 8. Acetous 9. Marine Acid Acid 10. Nitrous Acid FI. Vitriolic Acid 12. Aqua Regia 13. Nitre 14. Sulphur x5. Hepar of Sulphur 16. Cobalt I7. Arfenic 18. Regulus of Antimony 19. Glafs of Antimony Bifmuth 20. 21. Zinc Lead 32. 23. Tin 24. Iron 25. Copper 26. Silver 27. Mercury Earth ; Hepar of Sulphur Fixed Alkali Borax Calx of Lead Calx of Antimony Hepar of Sulpbur Fixed Alkali Borax Calx of Lead Calx of Antimony Clay Earth Calecareous Earth Gypleous Vitriolic = Acids Acid | § Hepar of Sulphur Fixed Alkali Borax Calx of Lead Calx of Antimony = 13 Hepar oF Sulpbur Fixed Alkali Boras Calx of | Lead Calx of Antimony Vitriolic Acid Nitrous Acid Marine Acid Acetous Acid Hepar of Sulphur Fixed Alkali Borax Calx of Lead Calx of Antimony Phlogifton Vitriolic Acid Nitrous Acid Marine Acid Vegetable Acids Zine Iron Copper Lead Tin Phlogifton Vitriolic Acid Nitrous Acid Marine Acid Acetous Acid Zine Iron Copper Bifmuth Mercury Phlogifton Copper Bifmuth Zine Zine Iron Iron Copper Tin Lead Lead Arfenic Phlogifton Bifmuth Regulus of Antimony Mercury Phlogifton : ne Iron Cobalt Copper Bifimuth Lead Mercury Antimony Silver Regulus of Phlogifton Zine Iron Copper Silver Tin Lead Mercury Bifmuth Regulus of | Antimony Zine Iron Cobalt Copper Tin Arfenic Bifmuth Mercury Lead Phlogifton Zinc Iron Copper Arfenic Lead Tin Cobalt Bifmuth Phlogifton Regulus of Antimony Iron Copper Tin Lead Silver Bifinuth Regulus of Antimony Mercury Arfenic Gobal: Gold Silver Iron Copper Lead Tin Regulus of Antimony Bifmuth Zine Cobalt Regulus of Copper Iron Tin Zine Antimony Bifmuth Lead Silver Arfenic (partly) Zine Iron Copper * Tin Lead Silver Gold Regulus of Antimony Zine Iron Copper Tin Lead Silver Bifmuth Gold Zine Copper Tin Lead Iron Silver Iron Copper Tin Lead Silver Gold Copper Iron Silver Gold Tin Lead (partly) Silver Copper Gold ‘Tin Iron Copper 8 ilver Gold Gold Silver Copper Gold Silver Gold Gold Silver Bifimuth Zine Tin Lead Copper Regulus of Antimony Mercury Regulus of Antimony Gold Regulus of Antimony Cobalt Arfenic Bifinuth BODIES NOT SOLUBLE BY THE SUBSTANCES PLACED AT THE HEAD OF Arfenic Tin | T Silver Arfenic Gold THE COLUMNS IMMEDIATELY ABOVE TH Siliceous Earth Siliceous Earth Siliceous Earth Calcareous Earth Siliceous Earth Gold Silver Gold Silver Gold Silver (partly by the Tin dry way) Mercury Gold Gold Silver Gold Silver Gold Zine Bifmuth Bifinuth Zinc Iron Iron Cobalt RE TABLE ofr AFFINITIES BETWEEN SEVERAL SUBSTANCES, BY Mk. GEOFFROY. I. Acid 3. Nitrous Acid 4. Vitriolic Acid 5. Abforbent Earth 6. Fixed Alkali 7. Volatile Alkali 8. Metallic Subftances 9. Sulphur 10. Mercury 11. Lead 12. Copper 13. Silver 14. Iron Regulus of] Antimony Water Abforbent Subflances Spirits Fixed Alkali Volatile Alkali Earths Metallic Regulus of Antimony Copper Silver Mercury Tin Iron Copper Lead Mercury Silver Phlogifton Fixed Alkali Volatile Alkali Abforbent Earths Iron Copper Silver Vitriolic Acid Nitrous Acid Marine Aeid Vitriolic Acid Nitrous Acid Marine Acid Acetous Acid Sulpbur Vitriolic Acid Nitrous Acid Marine Acid Marine Acid Vitriolic Acid Nitrous Acid Acetous Acid Fixed Alkali Iron Copper Lead Silver Antimony Mercury Gold Regulus of [Regulus of Gold Sileser Lead Copper Zine Antimony Silver Copper Mercury Lapis Calami~ naris Lead Copper Regulus of Antimony Iron Spirit of Wine Neutral Salts ; | $ ] : ft | i ; i - 3 B i | i 1 i 41 " : 1 fi Bi H i 5 : 3 : H | § i 1 ER | | 5 3 fi N b “1 Siliceous % Hepar af I. Earth Ze Fluors 3. Clay 4. Earth Gypfeous 5 Earth Calcareous Sulphur Fixed Alkali Borax Calx of Lead Calx of Antimony Sulpbur Fixed Alkali Borax Calx of Lead Calx of Antimony Clay Earth Calcareous Earth Gypfeous 1 Or wine, ana Hepar of Vitriolic|® Acid | § Hepar of Sulphur Fixed Alkali Borax Calx of Lead Calx of Antimony “= Acids | g QQ Hepar of Sulphur Fixed Alkali Borax Calx of Lead Calx of Antimony Vitriolic Acid Nitrous Acid Marine Acid Acetous Acid Hepar of Sulpbur Fixed Alkali Borax Calx of Lead Calx of Antimony ‘tapavic or which they could not unite with in their mild fate, | | | | | bitahces _The ATPFPINITITY +s ADOPTER. : 82¢ RECEIVER. : AFFINITY. By affinity (s) is underflood that ten= dency which the con have to unite, and that power by which they united. ituent or integrant parts of bodies: adhere when The definition of affinity thews that it is not a word void of meaning. ‘The power with which the parts of bodies tend to unite with éach other, and-their adhefion when united, are very fenfible and palpable eftects, fince this . The acidum pingue is fo fubtle that it pervades red-hot veflels, and combines with the bodies contained in them. It may be thus made to unite with metallic calxes, to which it imparts the greater weight which thefe bodies have than the metallic fubftances whence they were produced. It may be conveyed from thefe calxes by fire into alkalis, which thereby receive a cauftic quality. It unites with the vitriolic acid, when this acid is diftilled with {pirit of wine or other inflammable matters, or when vitriol is diftilled in a cracked veflel, and forms the volatile fulphureous acid. The acidum -pingue exifts naturally in the fulphureous caverns of Puzzoli, Pyrmont, &c. Meyer’s treatife is tranflated from the German into French by M: Dreux, under the title of Efais de Chymie fur la chaux vive, 2 vols. 1zmo. (s) By the terms affinity and elective attradion, we ought to underftand the power by which the conftituent parts of bodies unite, and not to fuppofe that this power is exerted by any fimi- larity and homogeneity of parts, or by any mechanical tration, as thefe terms feem to imply. The caufe of this power, or the manner in which this union of conftituent parts, is produced, is. unknown to us. To thefe terms, therefore, another lefs excep- tionable, namely, the power of combination, may be {ubftituted. In our author’s definition of affinity are comprehended not only the power by which the conftituent parts of bodies unite, which 1s the proper obje¢t of chemiftry ; but alfo, the power by which the integrant parts unite, which he calls the affinity of aggrega- tion, and which is treated of by writers on natural philofophy and mechanics under the terms attraltion, gravita hefion. tion, and co- Whether thefe two kinds of union are produced from the fame caufe differently modified, as our author thinks, 1 know not ; but their effets are fo different; that they deferve to be confidered feparately : the unien of integrant parts being only an appofition of thefe parts, which are capable of being disjoined by mechanical means, and without any change produced upon their properties ; and the union of confiituent parts, or combination, heing attended with confiderable changes of properties, and being incapable of disjunétion by mechanical means. CourossTioy of Bopigs, and the following Nose, ok. Ii See the article power ~ ———————————————— i ———— AFREINITY power cannot be deftroyed but by another power as real and more confiderable. It is befides demonftrated by numberlefs experiments ; as, for example, by the adhefion of two bodies applied to each other, whofe furfaces are finely polithed ; by the tendency which two drops of water, or of oil, mercury, or of any other fluid, have to run together and unite into one mafs ; by the convex or fpherical figure which drops of fluids affume, when their form is not given them by containing veflels or other body, and when they are fupported by bodies with which they are not difpofed to unite: all which effects happen even in a vacuum, and de- monftrate the affinity which the integrant parts of bodies folid, or fluid, have to each other. i j The affinity of the conftituent parts or principles is de- monftrated by the detail of all the phenomena in chem A's: We do not here enquire into the caufe of this great effect, which is fo general, that it may itfelf be confidered as the caufe of all combinations, and may ferve to explain them. It may perhaps be a property as eflential to matter as its extent and impenetrability, of which we can fay no more, than that fuch -properties do exift. On this fubjeét the works of Newton, Freind, Keil, and the Abbé Marcuzzi, may be confulted. Thefe authors have endeavoured to illuf- trate thefe obfcure fubjeéts by calculation. We fhall be fatisfied with obferving the moft remarkable laws, according to which the principles of bodies unite and combine, in con- fequence of this property. M. Macquer Siftingu fhes feveral forts of affinities. Not that he believes there are really different fpecies of affinities ; for it is very certain, that it is but one and the fame property of matter, differently modified according to different circumitances ; but only that he may better diftinguifh and remark the phenomena occafioned by this property, in the detail of the combinations and feparations which it effects in the moft general and moft important operations of chemiftry. By [imple affinity he means the difpofition to unite and adhere, which is obferved between the integrant and homo- geneous parts of the fame body, or between the heterogeneous parts of two different bodies. The fimple affinity is there- fore diftinguithed into two kinds. The firff kind of fimple affinity produces the union of aggre- gation ; that is to fay, that the body refulting from this union is of the fame nature, but of larger fize. M. Mac- quer calls it the affinity of aggregation; as, for example, when feveral loofe particles of the fame metal or of the fms | eart AFFINITY earth are united together by fufion, fo as to form but one mafs. See AGGREGATION. \ . The fecond kind of fimple affinity, producing the union and adherence of heterogeneous parts, ‘different in their natures, from which refults a new compound body, whofe properties are different: from thofe of the two principles from which it was formed, is called affinity of compofition ; becaufe a2 new body is aétually compofed. If, for example, the primitive integrant parts of vitriolic acid be united with thofe of iron, a new body refults from this union, which is neither vitriolic acid noriron, but a compound of the two, called martial vitriol. The following remarks may be made on fimple affinities. 1. That the affinity of aggregation refifts the affinity of compofition. For it is evident that the force which makes the homogeneous and integrant parts of a body adhere together, hinders them from feparating, in order to join the parts of another body. 2. Henceit follows, that if the achefion of aggregation be- tween the integrant parts of a body be weakened or deftroyed, the affinity of compofition is thereby facilitated ; thatis, the affinity which they have to join the parts of another body. 3. That as the hardnefs of a body fuppofed {imple and homogeneous depends only on the adhefion of aggregation betwixt its integrant parts, if this adhefion be dettroyed by feparating thefe parts from each other ; as by reducing them into fine powder, or ftiil more by diffufing them in a liquid, with which they have no adhefion, or leis than they had to each other; they may then be combined with the parts of another body, more or lefs eafily, in proportion as they have been more or lefs feparated by this mechanical divifion. 4. As different bodies are more or lefs fufceptible of this mechanical divifion,- whether artificial or natural, by which their integrant parts are more or lefs feparated from each other, hence arifes great difference betwixt thefe bodies in their greater or lefs facility of combining with other bodies. 5. The facility with which one body combines with another does not, however, folely determine the degree of affinity betwixt thefe two bodies. Tor experience fhews that the principles or conftituent pasts of certain ccmpounds, which unite together very readily and eafily, have however but a weak adhefion, which is deftroyed by the fmalleft effort of analyfis, or chemical decompofition; while other principles which can be united only with great difficulty, and by ftudied means, contra&t together an union much ~ 2 {ironger, AFFI'NTI'TY ftronger, and much lefs apt to be diffolved. Mercury, for in« ftance, unites much more eafily with nitrous acid than with the marine, but yet it adheres much more ftrongly to the latter than to the former. tans Hence we ought to conclude, that we cafinot pofitively determine that one body has no affinity with another body, becatife ne means are known of uniting them: On the contrary; it appears certain that all natural bodies have a certain degree of affinity, and of facility of uniting with cach other, and a certain degree of adhefion when they are united, and confequently, that there are no combinations really and abfolutely impoffible ; but that this degree of affinity varies according to the different ftates in which thefe bodies are found. However, as the want of union betwixt two bodies pre- vents their affinity from fhewing itfelf, we may confider thofe bodies which we cannot combine as if they had no affinity together, until chemiftry be fo far advanced as to make “combinations which now feem impoffible. Thus, for inftance, oil is faid to have no affinity with water, nor lead with iron, nor iron with mercury; becaufe, in fat, thefe bodies cannot be dire&tly united together in chemical operations. Thus any affinity which they may have to cach other is to. us of no confequence. On the contrary, as the affinities of bodies which may be united together, produce in chemical operations effets pro- portionable to their facility of union, and to their force of ad- hefion when united, we may confider the affinity of bodies in general, as being ina compound ratio of thefe two properties. ke laft remark we can make on the fimple affinity of compofition, furnifhes a very ufeful and very general fun- damental law, by which we may difcover, even without decompofition, the principles of which bodies are compofed. The remark is, that all compound bodies have properties partaking of the properties of the principles of which thefe bodies are compofed. Thus, for example, the union of two principles, of which one is fixed, and the other is vola- tile, forms 2 compound, whofe degree of fixity or volatility is intermediate betwixt thofe of the two principles. The fame may be {aid of all the other properties; fuch as gravity, opacity, tranfparency, dudtility, hardnefs, fluidity, %c. and even of the affinities : fo that, fuppofing we knew perfectly the properties of the principles of a compound, we might, by examining the properties of this compound, dif- cover its principles, even although its analyfis were impoflible. 3 We, ARFRINITY. We muft however allow that this rule, although very general, is fubje&t to a confiderable number of reftriétions and modifications, which depend on a number of particular circumftances. For example: it happens fometimes that the operation by which two principles are united changes or even annuls fome of “the properties of thefe principles: it happens too that fometimes their union developes new properties, which cannot be immediately perceived in either of the principles. But fuch changes are never fo compleat as to lead one into grofs miftakes concerning the principles ; - therefore they do not prevent the rule from being fuffi- ciently general, to be an excellent guide in many chemical enquiries. (2). Where more than two bodies act upon one another, the affinity may be called complicated; and from the definition given, it appears that all thefe complicated affinities muft be of the kind called Affinity of Compofition. Firft, we ought to confider that complicated affinity in which only three principles act. Experience indicates the following obfervations. If a principle be added to two other principles united to- (t) The rule mentioned in the text is fo far from being gene- ral, that perhaps the reverfe of it may be confidered as a general rule; and a change of properties, and a prodution of new pro- _perties, may be confidered as criterions, by which compound bodies, chemically combined, may be diftinguifhed from bodies formed merely by mixture or appofition of integrant parts; in which latter kind of bodies, the properties are intermediate be- twixt the properties of the feveral component parts, and no new properties are produced. Thus, three parts of copper combined by fufion with one part of tin, forms a body more hard, more brittle, and more fonorous, than either of the conftituent metals. Its hardnefs, therefore, its brittlenefs, and its fonoroufnefs may be confidered as new prope:ties. Its color is much whiter than the intermediate color, and its fpecific gravity is greater than the intermediate {pecific gravity. Further, the properties of bodies are in many inftances deftroyed or annulled by chemical combi- nation. Thus the acrimony and deliqu :ceacy of acids and of alkalies are almoft entirely annulled by combining thefe two kinds of fubftances together. Every body chemically combined may furnith faéts which refute the general propofition mentioned in the text. Bodies formed by mixing, not by chemically com- bining feveral fubftances together; as, for inftance, a liquor formed by mixing wine and water; partake of the qualities of each ingredient, proportionably to the quantity of it employed, See ComposiTION of Bopies, and AGGREGATION, D 3 gether AFFINITY . gether, phenomena of compofition of of decompofition Eero: which differ according to the affinities of thefe thiee bodies to each other. 1. Sometimes the third fupervening principle is united to th other two, and forms together with them’a compound confifting of three principles. For “example, if to a mafs compofed of gold and filver fome copper be added, this third metal is united to the other two, and forms with them a compound confifting of three principles, namely, gold, filver, and copper. Thus it happens, when the third fupervening principle has with the two others an affinity equal, or almoft equal to the affinity which thefe two prin- ciples have to each other, 2. The fame thing alfo happens fometimes, although the third fupervening principle has no affinity with one of the two principles originally united. But then it is necef- {ary that this {upervening principle fhould have, with the other of the two principles, an affinity equal to the affinity fubfiting between thofe two principles originally united, And in this cafe, that principle which feryes to conne& and unite the two which could not otherwife be united, is called an intermedium. ‘This affinity may alfo be called the affinity of intermediums. For example, if water be added to the Compound called liver of fulphur, which confifts of wo principlss, fulphur and fixed alkali, it unites with the water, diffolves in it without being decompofed, and forms a new compound confifting of three principles, namely, fulphur, fixed alkali, and water, The water and fulphur could not by themfeclves form any union: but as fixed aikali has a great aflinity with both fulphur and water, it ferves upon this occafion as an intermedium to unite thefe twa fubftances together. It is neceffary to remark, that in this affinity of intermediums, the affinity of the principle which ferves as an intermedium is weakened, becaufe it is divided betwixt two bodics; and that the union contracted with them is lefs flrong than if it were united to one of them aly. ) 3. Sometimes a third principle, when added to a com- pound confifting of two principles, does not unite but with one of thefe two principles, and obliges the other to feparate itfelf entirely from the principle with which it was originally united, In’ this cafe a total decompofition happens of the firft compound, and a new combination of the remaining principle with the fuperyening principle; from which a new compound refults, This happens when the fupervening principle AFFINITY principle has little or no affinity with one of the principles of the compound; and when it has with the other, an affinity much ftronger than that which {ubfifts betwixt the two firfk principles. For example, when an alkali is added’ to a folution of a metallic matter in an acid, as it has more affinity with the acid than with the metal, it feizes the acid, and obliges it to quit the metal, which therefore precipi~ tates; becaufe the metal has much lefs affinity than the alkaline falt has to the acid. 4. It happens fometimes that a principle, which, in con- fequence of the affinity we have been difcourfing of, has been feparated from another principle, may again refume its place with the principle, as it was originally, -and difpoflefs the fupervening principle. This affinity, which is called reciprocal, on account of its reciprocal effects, takes place when the two principles which are alternately feparated from - the third principle by each other, have with this third prin- ciple an almoft equal affinity, and that their feparation is procured by particular circumftances relative to fome of their properties. All that has been faid concerning the affinities of three principles may be applied to affinities of four principles, due regard being had to the changes produced by the introduction of a fourth principle. It is evident, for example, that in place of one decompofition and one new compofition, which can refult from the different degrees of affinity of three principles, the affinities of four principles forming two new compounds, may, by a mutual change, produce two decompofitions and two new combinations. This always happens when the fum of the affinities, which each of the principles of the two compounds has with the principles of the other, furpaffes the fum of the affinities fubfifting betwixt the principles forming the two firft compounds. This fort of affinity, where there is a double exchange of principles, may be called double affinity. Examples of thefe affinities are often met in chemical operations and mixtures; and without a knowledge of them, it would be impoffible to explain many fingular phenomena of decompofition. For example, it happens often that two principles, neither of which could fingly effe& the difunion of the principles of a compound, becaufe their affinities are each of them inferior to the affinity betwixt the principles of that compound, become neverthelefs capable of procuring this decompofition when they a&t in concurrence, For this purpofe, it is fuffi- cient, as we have already faid, that the fum of affinities D4 which AFFINIL TY which the two decompofing principles have with the prin< ciples of the body to be decompofed, fhould furpafs the fum of the affinity betwixt the principles of the decompofing body, and of the affinity betwixt the principles of the body to be. decompofed. See examples of this play of affinities at the ane BLuk (Prussian), and SALT (NEUTRAL ARSENI- CAL). We fhall purfue no farther thefe remarks upon affinities ; becaufe the affinities of bodies compounded of many prin- ciples are much lefs ftrong and lefs fenfible in chemical operations ; or becaufe this fcience is not yet fufficiently advanced to have obferved and diftinguithed them all. What we have faid is fufficient to form juft ideas on the theory of all the important phenomena which are exhibited by the fundamental experiments, and to conduét to many new difcoveries. See the annexed TABLES of AFFINITIES, with their EXPLANATION. (u) AGARIC. (z) Although many of the affinities contained in thefe Ta- bles are mentioned under the feveral articles of the fubftances to which they relate, in the following Dictionary, yet I thought it might be ufeful to place them in one view, as they are given by their authors Geoffroy and Gellert. . EXPLANATION OF THE TABLES OF AFFINITIES. Each of thefe Tables confifts of a number of columns. At the head of each column is placed the fubftance, the affinities of which are to be compared with the feveral fubftances placed below it in the fame column. Thus the firft column of Mr. Geof- froy’s Table contains the Affinities of acid fpirits; the fecond column contains the Affinities of marine acid, &c. The remaining fubftances in the firft column, as fixed alkali, wolatile alkali, &c. are thofe, the affinities of which with acid fpirits are to be com- pared together: and, they are fo difpofed, that the fubftance which has the ftrongeft affinity with acid fpirits is placed neareft . ta them, and the fubftance which has the leaft affinity with acids is placed at the greateft diftance; while the ftrength of the affinity of the intermediate fubftances may be known by their vicinity to the head of the column, Thus, acid fpirits have a ftronger affinity to fixed alkali than to volatile alkali, abforbent earths, or metallic fubftances: alfo, they have a ftronger affinity to volatile alkali than to abforbent earths ; and laftly, they have a fironger affinity to abforbent earths than to metallic fubftances. Mr, Gellert has (in his original Table) inverted this order, placing thofe fubftances at the greateft diftance, or at the bottom of the columns, which have the ftrongeft affinity with thofe 2 the AFFINITY" tlie head'of ‘the columns. But as this difference in the order of the two Tables might create fome confufion, I have changed this difpofition of Mr. Gellert’s Table, and have made it correfpond with that of Mr. Geoffroy which is above-defcribed. : According to the dottrine of affinities delivered under the article ArriniTY of this Di&ionary, any fubftance in any of thefe columns'may-be feparated from the {fubftance at the head of that column by any of the intervening fubftances. Thus, accord- ing to the firft column of Mr. Geoffroy’s Table, if any metallic Jubflance be united with an acid fpirit, it may be feparated from that fpirit, by adding either an abforbent earth, or a volatile alkali, or a fixed alkali: fecondly, if an abforbent earth be united with an acid fpirit, it may be feparated from that fpirit, by adding either a volatile or fixed alkali: and laftly, if a volatile alkali be united with an acid {pirit, it may be feparated from that acid by adding a fixed alkali. " To explain the ufe of thefe Tables fill further, I {hall give an inftance of the affinities of Julphur, as they are exprefled in Mr. Gellert’s Table. : 3 If fulphur be’united with regulus of cobalt . with which, according to this Table, it has lefs affinity than with any of the fubftances mentioned in this column, and if to this compound arfenic be added ; by fublimation the fulphur will be feparated from the regulus of cobalt, and will be united with the arfenic, forming a fublimate called orpiment. If to this orpiment an equal quantity of mercury be added, and if the mixture, after it has been well triturated, be expofed to heat in a retort, or other clofe veflel, the arfenic will be feparated from the fulphur, and will form a white fublimate ; while the fulphur and ‘mercury will unite, and be afterwards fublimed to- gether, forming a cinnabar. i If to this cinnabar a third part of regulus of antimony be added, and the mixture be expofed to heat in a retort, the mer- cury will be diftilled, and the fulphur will remain united with the regulus, forming a compound fimilar to native antimony. If to this artificial, or to native antimony fufed in a crucible, half its quantity of bifmuth be added, this femi-metal will unite with the fulphur of the antimony; while the regulus of the anti- mony will be feparated, and form a diftin& mafs at the bottom of the crucible. tin If this compound of bifmuth and fulphur be melted with an equal quantity of filver, the bifmuth will be feparated from the fulphur, which will unite with the filyer, forming a mafs fimilar to the vitreous filver-ore, * In the Table it is marked cobalt ; but Mr. Gellert evidently means the regulus of cobalt ; for the ore properly called Cobalt, contains yarious fubftances, each of which has peculiar affinities. See COBALT. If AFFINITY _ If this mafs, or the vitreous ore, be melted with half its quan- tity of lead, the filver will be feparated from the fulphur, which wiil unite with the lead, forming a mafs refembling the lead-ore called galena, i If this fulphurated lead be melted with tin, the lead will bs feparated, and the tin will be united with the fulphur. In the fame manner, the fulphur may be transferred from the tin to copper ; and from copper to iron, The aflinities of bodies to each other, as they are laid down in the above Tables, or at leaft the feparations and decompofi- tions depending upon the differences of affinities, do not at all times take place; fome of them requiring certain degrees of heat, dilution, and various other circumftances. Many inftances do alfo occur, in which the affinities of fubftances feem even to be changed by thefe different circumftances; and hence many ex- ceptions have been found to the prefent Tables, fome of which are real, and others only apparent. Thus, in the firft column of Mr. Geoffroy’s Table, metallic fubftances are placed as having a lefs affinity than abforbent earths with acids. Neverthelefs, fome inftances occur of earthy falts, as alum, being decompofed by means of metals, as of iron, zinc, and copper. Here there- fore we find a real exception to this Table. Again, abforbent earths are placed as having lefs affinity than volatile alkali with acids. But the volatile alkali of fa! ammoniac may be feparated from the acid, by means of chalk or quicklime ; which feems to fhew, that fome abforbent earths have a greater affinity with acids than volatile alkali. This alkali does indeed, when it is mild, precipitate a folution of any calcareous earth in any acid; and this experiment has probably induced Mr. Geoftroy to place thefe fubflances in their prefent order. But the above-mentioned pre- cipitation is now known to be effected by what Mr. Macquer calls a double affinity. For the mild alkali, confifting of pure alkali and fixable air or gas, is here to be confidered as a compound : and when it is added to a {olution of calcareous earth in any acid, the gas unites with the earth, to which it has a greater affinity than to the alkali, while the acid unites with the alkali. That this is the cafe, in the prefent inftance, appears from the impofii- bility of precipitating this earth from the acid by means of a caufiic volatile alkali, that is, an alkali which is not combined with gas. Many other inftances might be adduced of the inaccu- ra ies and defeés of thefe ables, and of the apparent variations from the general rules laid down in them; but as all chemical compcfitions and decomipofitions depend on the affinities of the fubftances employed, we cannot explain aud corre(t thefe, with- out .onfidering almoft all the operations in Chemiftry. Till other [ables mare perfeét be formed, thefe may be of confides- able utility. i EERE FE Gi = I CS a ea i, es SR Es can a AGGREGATION AGARIC. (=x) AGATE. (y AGGREGATION. In order to have a clear idea of what chemifts mean by the words aggregation, aggregate, aggregated bodies, we muft attend to the difference betwixt what natural philofophers call conflituent parts and integrant parts of bodies. The conftituent parts are, properly fpeak- ing, the principles of bodies. Thefe are fubftances differing (x) Agaric is a fungus growing on the trunk of the common larch tree, from which turpentine is obtained. Three-fourths of it is a refinous fubftance, and the remainder is a {limy mucila- ginous earthy matter, fo tenacious as fcarcely by any method to be diffolved by water. (y) AGaTe is a flint variegated with different colors blended together, and fometimes with colored lines and dendritical figures, as the mocha fone, which is a variety of agate, or with red {pots, as the fardea or §t Stephen’s gem, which alfo are varieties of this fione. For the chemical properties of agates, fee EARTHS (VitririasLe). By fire the color of a white agate, called chal- cedony, was rendered whiter, and the color of a black agate was not changed. Colors may be given to agates, or their natural colors may be changed. Mr. du Fay, in the Memoirs of the Academy of Sciences, 1728, relates, that to chalcedony a fatu- rated folution of filver in ftreng fpirit of nitre gave a reddith brown color, to oriental agate a blacker ftain, and changed the yellow fpots of an agate to purple. The fone after the appli- cation of the metallic folution ought to be placed in the fun; and the color may be rendered more intenfe by repeating the application of the folution. The liquor fpreads fo much on the fione, that neat defigns cannot be made on it. Dr. Lewis pro- pofes to remedy this inconvenience by covering the flone over with etching wax, and the lines intended to be ftained cut through this ground, in the manner of etching copper-plates. The colors given to thefe ftones may be deftroyed by fire or by aqua fortis ; and the colors thus deftoroyed by aqua fortis are recoverable by expo- fure to the fun. Agates and other flones may be ftained black by applying to them a folution of copper in aqua fortis, and afterwards expofing them toared heat in a crucible. See Leawis’s Commerce of 4rts. Mocha ftones may be imitated by moiftening the fmooth farface of an agate with the folution of copper, and cn the middle of this {urface fetting an iron nail upright on its head. The iron abforbs the acid from the copper, and the cop- per forms ramifications. If the nail be then removed, and the corroded iron carefully walhed off by dipping the ftone in water, the vegetations may be rendered by a red heat of a black color, Thefe vegetations are not fixed in the fone, which ought there- fore to be covered with a plate of cryflal glafs, in AGGREGATION in nature from each other, which, by their union and mu- tual combination, really conflitute mixed bodies, which par- take of the properties of their conftituent parts. For example, the conflituent parts of common falt are an acid and an alkali, which ought to be confidered as the principles of this falt, at leaft as its proximate principles. See PRINCIPLES. As this acid and alkali are what really conftitute common falt, and are the parts, to the union of which it owes its exiftence and properties, it is evident that the conftituent parts cannot be diiunited from each other, without deftroying and decom- pofing it: fo that after fuch a difunion, the falt will no longer exift, but only the acid and the alkali of the falt, which are very different from the falt, and from each other. On the contrary, the integrant parts of bodies do not abfolutely differ from each other ; nor do they differ, as to the nature and principles, from the body into whofe mafs they enter. By the integrant parts of a body are to be underftood the fmalleft molecules or particles into which this body can be reduced without decompofition. We may conceive that a neutral falt, for inftance, common falt, may be divided into molecules ftill fmaller and fmaller, without any feparation of the acid and alkali which contftitute the falt ; fo that thefe molecules, however {mall, fhall always be common falt, and poffefled of all its effential properties. If we fhould now fuppofe that thefe molecules are arrived at their utmoft degree of fmallnefs, fo that each of ‘them {hall be compofed of one atom of acid and of another atom of alkali, and that they cannot be further divided without a feparation of the acid and alkali, then thefe laft molecules are thofe which Mr. Macquer in his Chemical Lectures calls primary integrant molecules. In the fame manner that we conceive that a body may be divided into its primary integrant molecules, without any change of its nature, or other alteration than a diminu- tion of its bulk ; fo we may alfo eafily perceive, that if thefe primary integrant molecules, which are all homogeneous and of the fame nature, ‘and which are fuppofed feparated from each other, fhould be brought to unite and combine together, no new body, that is, a body of different natute, will refult from this union, but only a more confiderable mafs of the fame body : that is to fay, for inftance, that if the primary integrant molecules were common falt, their reunion would itill form common falt, only in a mafs fo much larger, as there is a greater number of thefe molecules united together. But it is the union of thefe homogeneous parts, AGGREGATION parts, of thefe primitive integrant molecules, which modern chemifts have called aggregation ; and they have called aggre- gates bodies confidered as refulting from their primary integrant parts, in oppofition to the names mixt and com-~ pounds, which they have given to bodies confidered as: refulting from the union of their conflituent parts, which are fubftances heterogeneous, and of different natures. The name of integrant parts, which has been given to- thofe whofe union forms aggregates, agrees well with them; becaufe, in fact, this union is a kind of addition or integra- tion (if fuch a word may be ‘ufed) of a certain number of parts of the fame kind, whence refults a fum, or a whole. It is very effential to obferve on the fubjeét of aggrega- tion, that we fhould have a very falfe idea of it, and entirely oppofite to chemical phenomena, if we underftood by this word nothing but a fimple juxtapofition of the integrant parts of bodies: for befides that, there muft be a real adhefion and intimate union of thefe fame parts with each other, fo that they cannot be feparated but by fome force fuperior to that by which they are united. A heap of fand, for example, if we confider the grains of {and as its integrant parts, cannot be regarded as an aggregate, becaufe thefe grains are only juxtapafited, and have no real adhefion to- gether; fo that the refiftance which they oppofe to their feparation can only proceed from their gravity, and is not the effet of adhefion, or tendency to each other. In the fecond place, it is neceflary to obferve on the fubje& of aggregation, that the force of adhefion of the integrant parts of different bodies varies much, according to the nature of thefe bodies, fome of them adhering very ftrongly, and others very weakly; and that thofe which adhere weakly are generally the eafieft to be diffolved, con- fidering that the folution of a body, or its combination with another body of a different nature, cannot be effeted but fo far as the integrant parts of thefe bodies are feparated, or their aggregation is broken; which is partly done by the operations of art, but chiefly by the action of menftruums. All thefe confiderations on the aggregation of bodies, although very fimple in themfelves, are of the greateft importance in the theory and practice of chemical opera- tions. Becker and Stahl were the firft who explained thefe ideas, which have been fince illuftrated and extended by the beft modern chemifts. See the words, AFrinNiTy, Composition, SoruTIioN, DEcomrosition, Division of BopIEs. AIR, Ab RB AIR. Air is a fluid invifible, inodoreus, infipid, ime perceptible to all our fenfes but the touch, and is confidered as a fimple elementary body, and primary principle, be- caufe it cannot be altered or decompofed by any known methods. ; The air is always in form of a fluid, though perhaps that fluidity is not eflential to it. But it is certain that no cold has ever yet been produced, natural or artificial, ftrong enough to deprive it of its fluidity. We cannot flatter ourfelves that we can have air, any more than the other elements, in perfect purity. On the contrary, it is always found mixed with more or lefs of foreign fubftances, proceeding from a perpetual exhalation of volatile matters, and particularly of water, with which it has even a certain degree of adhefion. The primary integrant parts of air, although certainly very fmall, yet are not fo {mall as thofe of water, and even thofe of other liquids lefs fimple, fuch as fpirit of wine and oils: at leaft, thefe liquids pafs eafily enough through the pores of feveral fubftances, fuch as paper, the fkin, &c. through which the air does not pafs, or pafles with diffi- eal he experiments of Mr. Boyle, and more particularly thofe of Dr. Hales; related in his Vegetable Statics, prove that moft vegetable and animal matters contain a prodigious quantity of air ; and fcarcely credible, if the effects it pro- duced were not fo confiderable and fenfible. = Chemical experiments alfo give us many occafions not only of obferving thefe phenomena, but alfo of afcertaining the quantity of air difengaged, or abforbed in feveral operations. (z) It appears that air, as well as other primary principles, is found in bodies in two different fates: that is to fay, that in certain bodies, and in certain circumftances, it is merely difperfed and interpofed betwixt the integrant parts of thofe bodies, but-without adhering to thefe parts, or at leat adhering but very weakly. This air, which may be feparated by means purely mechanical ; fuch as the opera- tions of the air-pump, compreffion, or fhaking; and which befides poflefles all its other properties, ought not to be con- fidered as one of the elements of thofe bodies in which it exifts. But that portion of air which cannot be feparated (z) The permanently elaftic fluids produced in diftillations and other chemical operations are very different in. many effential pro- perties from atmofpherical air. See Gas. : rom 2 ® BR from many bodies but by analyfing them, and oy employing fuch means of decompolition as chemiftry furnifhes; which, befides while it remains in thofe bodies, is deprived of one of its effential properties, its elafticity, which it does not recover till it is difengaged ; this air, I fay, ought truly to be confidered as one oi the elements or conftituent parts of thefe bodies. The properties of pure air, and which occafion many effects in chemifltry, are: - 1. Its expanfive power; that is to fay, that it is capable of great rarefadtiori, and of occupying a fpace thirteen times larger than its original fize, when it is expofed to the greateft poffible heat. This great expanfibility of air, added to the prodigious quantity of it which is difengaged in many chemical analyfes and mixtures, occafions frequently violent explofions, againft which an intelligent artift ought always to be on his guard. (a) 2. Its compreffibility; that is to fay, that the effect contrary to that we have been mentioning, is produced upon it by means of cold and of prefiure. 3. Its elaflicity; which is nothing elfe than the force with which it endeavours to refume its natural condition, when it is violently rarefied, comprefled, or condenfed ; and the effort which it makes for that purpofe upon bodies which oppofe its re-eftabli{hment. 4. Its weight ; which determines it to fall impetuoufly into all the fpaces into which it can have accefs, and which are unoccupied by air, or more ponderous bodies. The experi- ments which demonftrate all thefe properties of the air are fo numerous and decifive, that nothing is better known and illuftrated in natural philofophy. On this fubjet may be confulted the works of Pafcal, Boyle, Mariotte, Abbé Nollet, and, in a word, of all the experimental philofophers. It (a) Air is expanded } of its bulk by the heat of boiling water. See the Hiftory of the Academy of Sciences 1669. Hales found that the air in a retort, when the bottom of the veffel was juft be- ginning to be red-hot, was expanded to twice its former fpace, and in a white or almoft melting heat it occupied thrice its former fpace or more; and Mr. Robins, a very accurate experimental philofopher, found that air was expanded by the heat of iron juft beginning to be white to four times its fize. As greater expan- fions cannot be well eftimated, I prefume there is an error in that part of the text to which this nete refers, where the air is {aid to be capable of expanfion to thirteen times its ordinary bulk. 18 A.B BR is only neceflary to obferve here, that the fpecific gravity of air is to that of water, nearly as 1 to 850. ) 5. The faculty which the air has of confiderably facilitat- ing the evaporation” of volatile matters fublimed by the fire. It is a well eftablithed fa in chemiftry, that the accefs of air greatly accelerates all evaporations and diftillations. We fee, for example, that by directing the blaft of bellows upon the furface of any volatile body evaporating by means of fire, as water, antimony, mercury, &c. that the f{moke or vapors of thefe bodies are very fenfibly encreafed. It is alfo cer- tain that any diftillation of a liquor, as of water, is much haftened, by direting upon its furface in the inner part of the alembic, the wind of a ventilator, as an Englith author has propofed. See DISTILLATION and EVAPORATION. 6. Laftly, the moft fingular property of air, and at the fame time one of the moft interefting in chemiftry, is, that no combuftible fubftance can burn without its accefs; and that the more ftrongly it is impelled againft burning bo- dies, the more rapid is the combuftion. Hence it follows, that as moft chemical operations cannot be performed with- out the affiftance of fire, a conftant current of air more or lefs ftrong, and in a certain direction, is neceflary to produce the heat requifite in thefe operations. Thefe currents of air are procured by bellows applied either to a forge, or to a melting furnace; or they are procured merely. by the conftrution of the furnaces; which is done in fuch a manner, that by means of a {pace left in the upper part of the furnace, in which the heat keeps up a perpetual vacuum, the external air is determined and forced to enter by the ath-hole, to fill the vacuum above, and confequently forms a current which conftantly pafles through the fire, and which is fo much more ftrong and rapid as the vacuum of the furnace above is greater. That is a fundamental principle from which general rules may be deduced, applicable to the conftru&ion of all poffible furnaces. Sez BELLows, FoRrGE, and FURNACE. Boerhaave, in his Treatife on Fire, and M. Geriké, Doctor of Phyfic, and Member of the Royal Academy of Berlin, who has alfo given a very large Differtation on Fire, in a very good work, printed in 1741, entitled Fundamenta Chymie Rationalis, are of opinion, that the acces of air is neceflary to the combuftion of fubftances; becaufe, by its weight and fpring, it keeps the flame conftantly applied to the combuftible body, and encreafes their contact. p ut A: 217 :R But this theory does not fufficiently explain why com= - buftible bodies may be kept red-hot in clofe veflels, without any confumption ; becaufe then it cannot be doubted but that the matter of fire is; by the movement excited during ignition, continually applied; and even impelled upon the combuftible body, without its burning or confuming. It has then all the appearance of a body burning and pene- trated by fire, but it is by an extraneous fire that it is fo penetrated ; its own inflammable matter is not confumed, and refts unalterable ih midft of a moft intenfe fire. However this be, it is very certain that the accefs of air is indifpenfibly neceflary to maintain the combuftion of bo- dies. But itis at the fame time very difficult to find the true caufe of this fact. = The phenomena of combuftion feem to prove, that the air materially concurs to the production of flame, and makes a part of it: for a given quantity of air can maintain only, during a limited and determinate time, the combuftion of a certain quantity of inflammable matter. If, for example, a lighted wax candle be placed under an inverted glafs bell, which is joined exactly to its fupport, the flame of the wax candle f{ubfifts during a certain time, fo much longer as the bell is larger, but conftantly diminifh- ing till at length it is extinguithed ; becaufe the quantity of air contained in the bell being a determinate quantity, and ‘not capable of being renewed, cannot ferve but for a certain quantity of combuftion. - Another phenomenon worthy of obfervation in this experiment is, that after the extin&ion of the wax candle, a real vacuum is formed under the bell, which is then as ftrongly prefled upon its fupport, as if a vacuum had been made by an air-pump; which proves demonftrably that the air HN it included, materially con- curred to the production of flame; fince, if it were not fo, the air being greatly rarified by the heat within the bell, would, on the contrary, make an effort to raife itfelf, and would efcape violently as foon as it could. : If we reflek-but a little on thefe phenomena, many Justtions occur very interefting, but at the fame time very difficult of folution. In fact, does the air, which difappears in this experiment, form a new compound with the inflam mable principle of the burnt body by a new combination ? If it be fo, what is this compound { and what becomes of it? or is the air itfelf a neceflary pabulum or food of flame? Is it decompofed by the act of combuftion? If fo, the air is not a fimple body: what then is the nature of its principles? and what becomes. of them? Vor. I. E » AIR ALABASTER AIR (FIXABLE); and air (Fixen); See Gas. ALABASTER. "The name Alabafter is given to flones externally refembling marble; of a hardnefs nearly equal, but inferior; and fufceptible of a fimilar, but lefs lively and fparkling polith. Seme alabafters are white ; and others are veined and colored, like marbles. When thefe ftones are well polithed, their femitranfparency, which is . more fenfible than that of marble, gives them the appearance of agates. Naturalifts difagree in their opinions about the kinds of {tones which ought to be called alabaflers. * For fome authors give this name to certain ftones which are abfolutely calca- reous, while others give it to ftones of a gypfeous nature. Of the latter clafs of naturalifts is Mr. Pott, who admits no calcareous alabafter, and firmly maintains his opinion in his Lithogeognofia againft Linnzus, Konig, Bruckman, and feveral other authors, who clafs alabafter along with marbles and calcareous ftones. It cannot be doubted that the ftone which Mr. Pott called alabafter, and which he chemically examined, is alually gypfeous. His ‘experiments evidently demonitrate it. * But, on the other fide, it does not appear lefs certain, that the name alebafler has been very anciently given to ftones undoubtedly calcareous. The greateft part of the antique vafes and bufts, although univerfally called alabafter, are of this kind. ‘They are readily and entirely foluble in fpirit of nitre with great effervefcence, and are convertible by fire into quicklime. The truth is, that fculptors and artifts, who work upon marble and alabafter, feem to have given indifcriminately the n-me alabafler to ftones which have only an external refemblance to each other; that is to fay, to flones which, to the other external qualities of marble, join alfo 2 mere cryftalline and more tranfparent appearance. Thus thefe artifts have confounded under one name ftones of very dif- ferent kinds; and hence, among thofe called alabafters, fome are truly calcareous, and others entirely gypfeous. Therefore if ftones are to be named from their external appearances, we ought, in order to avoid a confufion of two fubftances entirely different, to admit two kinds of alaba- fers; one kind calcareous, of which the greateft part of * vafes and bufts are made which are called alabafter; and the other kind gypfeous, which is alfo ufed in fculpture, and is that which Mr. Pott examined, and to which he affigns exclufively the name alabafter. cua Thefe - -A-L.-E M.B.1 C __ Thefe difficulties being explained, chemifts and naturalifts are at liberty to take which fide they pleafe. They will -always be underftood when they diftinguifh in this manner the {ubftances concerning which they write. This being eftablifhed, the kind of ftone which may be called calcareous alabafter, has eflentially all the proper- ties of calcareous ftones ; for which reafon, it is neceflary to confult, upon this fubje&, the articles EARTHS (cAL- cAREoUs) and QuickiIME. We fhall only obferve here, that it appears demonftrated, as M.d’ Aubenton has advanced, that the differences obfervable betwixt the calcareous alaba- fter and marble, proceed only from the different manners in which thefe two fubftances are formed; marble being of ancient formation, and the product of a depofition of en reous particles accumulated upon each other in banks and large mafles : while calcareous alabafter is formed allo of calcareous particles, but in the way of filtration; and of Slalattites, of which large enough mafles are found to make vafes, bufts, and even f{tatues. This difference in the for- mation of thefe two matters is fufficient to explain the caufe of the greater tranfparency of calcareous alabafter. In fad, if a piece of calcareous ftaladtites be cut and polifhed, no difference can be perceived betwixt it and works made of calcareous alabafter. As to the ftone called gypfeous alabafler, it has all the pro- perties of gypfeous flones, and therefore it is neceflary to confult upon this fubject the articles Gypsum and PLasTER. ALCHEMY. This term has been employed by the pretended adepts, and by fearchers after the philofopher’s fone, to diftinguifh that kind of chemiftry, the knowledge of ‘which they flattered themfelves was referved for them alone. The adepts confider chemiftry as a vulgar {cience, which fearcely contains the firft elements of the myfterious fcience of alchemy. But hitherto they have produced no- thing which, in the judgment of fenfible men, can give the leaft grounds for {uch a pretention. True chemifts confider alchemy as an imaginary {cience, and thofe who are devoted to it as perfons who, from want of better inftruétion, quit a reali for the fake of a thadow. ALEMBIC. An alembic or fill is a veflel employed in diftillations. There are feveral kinds differing from each other, either as to their form, or the matter of which they are made. The moft frequent ufe of alembics is for diftillations of very volatile principles drawn from feveral {ubftances, par- ticularly from vegetables. When the principles intended to 2 be A L'E'wn1°c be procured by diftillation have no confiderable ation upon metals, and when they are fufceptible of rifing with a degree of heat which does not exceed, or but little, the heat of boiling water, copper alembics well tinned in their internal furface are employed. The moft convenient of thefe alembics, and which may be employed for many kinds of diftillation, are compofed of the following pieces. The firft is 2 kind of pot defigned to contain either the matters intended for diftillation, or water, in which is immerfed another {fmaller veflel of the fame form, and made to contain the matters intended for diftillation by the water-bath. Thefe pieces of the alembic are called in general cucurbits; becaufe formerly they were of an oblong form, upright, contra&ing themfelves in their upper part, and diminifhing into a kind of neck, which made them refemble a cucurbit, or gourd, or a bladder, by which latter name alfo they have been diftinguifhed. The cucurbits of copper alembics ufed now have no refemblance to this form : on the contrary, they are broad, not very deep, and wide. This new form of cucurbits is much more advantageous, as by it the diftillations are much accelerated, with equal heat. The reafon of this is, that the quicknefs of diftillation is always proportionable to the ‘quicknefs of evaporation ; and that as evaporation is always “made at the furface of bodies, the more furface thefe bodies | poles, the more quick and eafy will be the evaporation. ‘But the broad and wide form of modern cucurbits is in- finitely more proper for the expofing of much furface of the bodies contained, and particularly of liquid bodies, than os form of the ancient cucurbits, which were high and rait. The firlt of thefe two picees is of copper, that it may refift the action of the fire: the fecond is generally of tin, ‘and ought to be fo fhaped, that it can enter exaétly into the former piece, and that they fhould fit fo well as to render any luting unneceflary. here ought to be a fmall pipe or neck at the upper part of the firlt piece, which may be exactly clofed, and through which water or other fluid may be introduced at pleafure. - The third piece of the alembic is called the capital, be- caule it is a kind of head. This piece has the form of a hollow cone. It is furnithed with a gutter or channel, which is placed along its inner and lower circumference. This capital has alfo_in its lower part a kind of neck, which ought to enter fo exactly into eicher of the two CT formes ALEMBIC former pieces, as #0 luting fhall be neceflary. Laftly, it ought to have a pipe, called the beat, which opens inwardly into the gutter. This beak ought to be from fifteen to eighteen inches ex- ternally, and fo inclined, that it fhall make with the neck of the alembic an angle of about fixty degrees. The fourth piece of a copper alembic is called the re- frigeratory. It is a kind of bucket, furrounding the capital, to which it is exa&ly foldered in its lower part. In this, near its bottom, «is inferted a cock. - The ufe of the refri- gratory is to contain cold water to facilitate the condenfa- tion of vapors circulating in the capital. Its cock ferves to emipty the water when it is become too hot, that it may be fupplied with cold. ny ol "As in copper alembics, the refrigeratory and capital are joined, they may be confidered as making only one piece. However, it is neceflary tq diftinguifth them ; rit, becaufe their ufes are very diffrent and, fecondly, becaufe the refrigeratory is not effential to the ale: bic. Several chemifts, good operators, are doubtful concerning its utility, particu- Tarly fince the cuftom was introduced of applying worms to alembics,- ., - 2 "The worm js a long, tin, fpiral pipe, included in a copper bucket, fo that its upper and lower extremities fhall come out of the bucket by two holes, round which they are well foldered. The upper extremity of the worm receives the beak of the alembic, and its lower extremity enters into a receiver fitted to it. The bucket containing the worm is filled with cold water, which cools and condenfes the vapors pafling through it. The principal advantage which this refrigeratory has over that urrounding the capital, is, that it is not fubje to retard or even to ftop the diftillation, as this latter one is: for this inconvenience has béen ob- ferved to happen, whenever the capital of the alémbic has been expofed to a certain degree of cold. There is in M. Beaumé’s Elements of Pharmacy a very exaét defcription, and a good engraving of a copper alembic with its worm. The alembics defcribed are of great ufe for the diftillation of the fpiritus rector of vegetables, of their diffilled waters, of their ¢fféntial oils, of pure ardent Jpirits, of fpirits charged with the odoriferous principles of plants, and alfo for many other -diftillationis of this kind. But as it is frequently neceflary to diftill in alembics acid and faline liquors capable of attacking metals, glafs alembics are employed for fuch diftillations : and thefe are generally compofed of only two E 3 pieces, A LX AL pieces, namely, a cucurbit, and a capital, which is fitted above and joined by luting. There are glafs cucurbits, high and ftrait, which may be ufeful for the diftillation of certain very volatile fubftances.. Others are made {hallow and broad, and thefe have the fame advantages from their form as the metal ones have. oil To avoid the luting of the capital with the cucurbit, thefe glafs alembics have been made of one entire piece. The capital of thefe alembics, which are of cryftal glafs, ought to have an opening at its top, which may be exactly clofed with a cryftal flopper ground with emery. This opening is intended for the introduction of matters to be diftilled, and for the extraction of the refiduums after diftillation. Thefe alembics of one piece, although fometimes convenient, are feldom employed on account of their dearnefs,' and of the. difficulty of introducing, and of extracting folid matters. T here are alfo made cuctirbits of ftone-ware, and of glazed earthen ware, which are ufeful in many cafes. See at the word DISTILLATION feveral .objervations relative to the form and matter of sends Sec Plate I. wiih } ALKAHEST. This is a name given by ancient chemifts to a pretended univerfal menftruum, Such a men- firuum either does not exift, or elfe there is not any body in. nature which may not become an alkaheft, "For although certain fubftances have not hitherto been combined with others, the daily difcoveries in chemiftry of combinations formerly believed impoffible, feem to prove, that by certain management, and certain circumftances, any fubftance may be combined with all others; or, in other words, that a 1 bodies may be diffolved by an {ingle fubftance (2). " ALKALESCENT, This word is employed to de- note a matter {lightly alkaline, or which begins ‘to turn to the alkaline and putrid fermentation. ah ~ ALKALI 5 IXED). Fixed alkali is a fubftance * compofed of acid, of earth, and of a little phlogifton; and whofe principles have to each other a weaker adhefion, than the principles of any acid have to each other.’ There are feveral kinds of faline alkaline fubftances. “Thefe are vege- table alkali, mineral or foffile alkali, and volatile alkali. They are all called by the general name Alkali, becaufe the following properties are common to them all. * 4) Kunckel very well fhews the abfurdity of fearching for an — folyent by afking, ¢ If it diffolves all fubftances, in what veflel can it be contained?” ~~ oo RaW T AE ee 1. Alkalies ALKALI 1. Alkalies may eafily be obtained dry and concrete, and freed from all water unneceflary to their faline eflence (c). When they are in this ftate,. : : 2. They produce heat by adding water to them. 3. They attra& the moifture of the air, and deliquiate into Al (4). Coss af Foi : 4. They chan color o 1p of violets into gree A a Ryo fluid (e). or Be 5. They have an acrid, burning tafte, fo much ftronger as they are purer and dryer. ‘This tafte has fomething ursnous; and hence they are called by fome chemifts wrinous falts. They are alfo called Lxiwvial falts, becaufe the method of obtaining fixed alkalies confifts in lixiviating the afhes of certain vegetable fubftances. 6. They partly exhale with water, particularly when boiled in open air. 7. When they are dryed and re-diflolved, fome earth is always feparated from them. 8. They may be fufed by a moderate heat. 9. When fufed, they diflolve all earths. 10. When added to earths, and particularly to thofe called vitrifiable earths, and expofed to a fufficient degree of heat, they and the earths become glafs. See VITRIFICATION. 11. When added in a large proportion to the earths with which they are fufed or vit fed. they communicate to thefe earths all their own properties. See L1QUor of FLINTS. 12. They effervefce and unite with acids to the point of faturation more perfetly and more intimately than pure orien earths, and from this union refult difforcnt neutral alts. 13. They decompofe all falts with bafes of earths, metals, or volatile alkali. - "They feherase thefe bafes, and unite with the acids of the falts, with which they form new neutral falts. This is an example of ftronger affinity, from whence refult a new decompolfition and a new combination, (<) Volatile alkali tetains water fo firenglv, that it cannot be obtained dry, unlefs 2 combining it with fixable air, and then i becomes yfeiaat : The fixed Flakies may be rendered ry by applicatiop of heat, but are en cryftallizable by help of fixable ar See Gas 157 yes (4) Mineral alkali does not deliquiate by expofure to air; but on the contrary, when cryftallized, it is apt to become dry, and to lofe the water which is neceffary to its cryftalline ftate. (¢) Concerning the effeéts of acids and alkalies on the color of fyrup of violets, fee the note (d) fubjoined to the article, Acip. E 4 Alkaline ALKA AL??? Alkaline falts being fubftances pretty fimple, as well as 2cids, are powerful folvents. They are capable of combining not only with all acids and with all earths, as we have faid, but alfo with fulphur and with oily matters, = With fulphur they forni a fulphureous foap, foluble in water, called liver of [ulphur; which fee. A 4 Jif With oils; fat, refinsy &c. théy form compounds, which have been called foaps. In each of thefe combinations, the alkali is 2a medium .by which the’ inflammable fubftance, naturally unfoluble, and even immifcible in water, becomes mifcible and foluble in that liquid. = See Soar. Thefe faline fubftances can act alfo upon fpirit of wine, when they are deprived of all the water unneceflary to their eflence as falts. Alkalies, in that ftaté, applied to fpirit of winey firft. deprive it of “its fuperfluous water ; afterwards, when in a proper proportion, fey a& upon.itsown fubftance, by combining with if, and caufing feveral alterations, and even a decompofition of its parts. See SPIRIT of WINE (TARTARISED), and TINCTURE of SALT of TARTAR. Laftly, alkalies. a upon-metallic fubftances with. more or lefs facility, according to. their natures, and the different means employed; which fhall be mentioned under the fe- veral articles of the alkalies and metals. [ 7» : N. B. All that has been faid above ¢oncerning alkalies, may be applied to all the feveral kinds of alkalies, even to thofe called wolatile, excepting: thofe properties which depend upon fixity. Hence this article is applicable to alkalies in general. But it is neceffary to obferve, thata very juft idea cannot be formed of thefe generalities, without entering into. the details of what concerns the feveral kinds. See I the. affinities of fixed alkalis and for its medicinal virtues, the word ArLkAvrl (Fixep MINERAL). {1 .. ALKALI (FIXED VEGETABLE). This name is given to all fixed alkalies obtained by burning any vege- table fubftances, and which have not the properties of the alkali, which is the bafis of common falt, which has been called the alkali of common falt, the marine alkali, mineral or folfil alkali. 3 ; go The common method of obtaining fixed alkalies from vegetable fubftances, confifts in burning thefe’ fubftances freely and in open air, till they be reduced to athes. = See ComBusTioN of PLANTS, After which thefe afhes are Jixiviated with very pure water, till the water comes from them infipid. This lixivium is evaporated to drynefs; and what remains is the fixed alkaline falt of the plant, which may ALKALI hay be deprived of its fuperfluous water and fuperfluous phlogifton by calcination with a long and gentle fire. Fixed alkalies obtained from any vegetable matters when well prepared and carefully purified by means hereafter to be defcribed, are all exactly alike, and have the fame pro- perties; fo that they are only one and the fame kind of faline fubftance. But as it is very difficult to procure this falt in its utmoft degree of purity, and as, in this refpect, there is a difference betwixt thofe obtained from different vegetable matters, fome of them being naturally purer or more eafily fufceptible of purification than others; and fur- ther, as fufficient attention has not been given to the means of perfectly purifying thefe alkalies, two inconveniences have happened. The firft is, that feveral chemifts have imagined that there was an eflential difference betwixt alkalies obtained from different plants: and the fecond is, that other chemifts have attributed to alkalies in general, feveral properties not belonging to them as alkalies, but to certain foreign fubftances ad ering to them.” We here con- fider the vegetable alkali perfeltly purified: and after we have enumerated its principal properties, we will treat of its ‘origin, of its formation, and of the means of purify- ing it. Fixed vegetable alkali has all the properties related under the article ALkaLi (Fixep). - " ¢ It is folid or concrete, like an earthy fubftance; of a fine white'color; without tranfparency, or ¢ryftalline and regular fhape, becaufe, in fad, it is not fufceptible-of cryftalliza- tion (7) ; of no fmell while it is dry, but of a flight lixivial fmell when moiftened with water. It has a violent, -fharp; burning, cauftic and urinous tafte; that is to fay, that when put in the mouth, it difcovers a tafte of putrified urine,” which is caufed by the difengagement of volatile alkali from animal fubftances, - Here it is proper to obferve, that wlen it is required to tafte fixed alkaliy it is’ convenient to diffolve and dilute it in much water, which only leflens its ftrength without altering its character: otherwife the tongue might be bliftered, be- (f) Fixed vegetable alkali does not fo readily cryftallize as mineral alkali does. It is neverthelefs cryftallizable by expofing it to the permanently elaftic fluids produced by the 40 of alkaline fubftances with acids, by the combuftion of vegetable and animal fubflances, and by other methods. See Gas. caufe ALKA ATLTIL caufe calcined alkali is powerfully cauftic, and quickly corrodes and deftroys all animal matters (g). Fixed alkali, expofed to air, attracts moifture, with which it refolves, or deliquiates into a white tranfparent. colorlefs liquor like pure water. Fixed alkali attraéts thrice its quantity of moifture, according to ‘Gellert, Chemie Metallurgique, Tom. 1. p. 26. : : The fame thing happens if it be purpofely diffolved in water. But in this latter cafe, at the. rit inftant of the mixture, a pretty ftrong heat is excited by the aivity of the union of alkali and water, This heat, however, is much, lefs than what arifes from the mixture of concentrated vitriolic acid and water. Every time that fixed alkali is diflelved in water, a por- tion of indifloluble matter remains. If the folution be filtered, it pafles very clear: but after fome time, it begins. to be turbid, and fmall flocks are formed in it of a matter which falls to ‘the bottom of the veflel, and cannot afters wards be rediffolved. This matter is of the fame nature as the firft fubftance which we obferved remains undiflolved ; and is nothing elfe than a portion of the earth of the alkali, which is feparated every time that the falt is calcined and, diffolved. ‘The part which at firft pafies through the filter, and which afterwards renders the liquor turbid, is that part which was the moft attenuated, and moft adhering to the, alkaline falt. ~ This earth thus feparated, is no longer ina faline ftate, and confequently becomes, indiffoluble in water, like pure earths. Alkali diffolved in the fmalleft poflible quantity of ‘water; forms 2 liquor lefs fluid, more thick and unctuous than pure water, and which paffes with more difficulty through the filter, from the quantity of faline matter with which the water is charged. When it is touched and rubbed betwixt the fingers, it appears to have a fat and oily nature ; which proceeds from the greafy particles of the {kin diffolved by it. Thefe. properties have occafioned it to be called, but impro-: perly, an oil, by ancient chemifts. See OIL of TARTAR, It ought to be called the Liguor of alkaline Salt. * Dry fixed alkali, expofed to 2 moderate fire, that is, 2 little more than cherry red, fuftains its action pretty well, altho’ it fufes, and diminifhes in quantity. But by a very (zg) The caufe of this is, thatby calcination fixed alkali is de-- prived of a part of its gas, and is thereby rendered more folubley: and confequently more cauftic, Se Gas. violent ALKALI yiolent fire, the greateft part of it is diffipated in vapors, o even all of it, if the heat be fufficiently long and intenfe, It js eafy to be convinced of this, by obferving the pots in which glafs is melted in glafs-houfes. Above thefe pots a perpetual fmoke may be feen, which can proceed only from the fixed alkali which enters into the compofition of glafs; the other matters which enter into that compofition being papery more fixed than it. Fixed alkali is a very powerful folvent, In the dry way, and by help of proper heat, it diffolves all calcareous, vitri= fiable, argillaceous, gypfeous, and metallic earths; and in certain proportions, and nearly in equal parts, it changes moft of ‘thefe into different kinds of hard, folid, and tranf< arent glaffes. See GLAsS, VITRIFICATION, CRYSTAL~ Grass. When a third or fourth part only of earth is added to alkali, they more readily fufe, and unite together : and as the alkali is the prevailing principle in the new compound which refults from this union, fo its properties alfo prevail. Hence it renders the earths fo diffolved, foluble in water, and in acids, and fufceptible of attraéting the moifture of the air, &c. See L1QUor of FLINTS, 11s The alkali appears to have no a&ion by the humid way upon fubftances purely earthy ; but it has upon quicklime, to which it gives, and from which it receives, very fingular alterations, When it is liquid, and treated with this fub- ftance, it becomes infinitely more cauftic and more fufible than it was hefore. See Lixivium of SoAR-BOILERS, CAvTERY (bh). | : _ Fixed Jogeighis alkali unites with the vitriolic acid violently and with great effervefcence. ‘The union of thefe: two faline fubftances is very ftrong and very intimate; and from thence refults a perfe&t neutral falt, which is vitriolated tartar. See TARTAR (VITRIOLATED). With nitrous acid it forms aitre, a neutral cryftallizable falt, the properties of which fee under the word N1TRE. With maripe acid, fixed vegetable alkali forms a particular kind of common falt, refembling in many refpects the native common falt, but differing from it in others, and chiefly in its tafte, which is much lefs agreeable than that of (8) The cautlicity which alkaline {alts acquire by being treated with quicklime, is occafioned by this fubftance depriving them of their gas, to which ithas a ftronger power of combination than: they have, See Gas. REE | common Al KALE common falt. = The differences betwixt thefe two falts are caufed by the difference of their alkaline bafes, native com- mon’ fait having for) its bafis a particular kind of fixed alkaline falt, which differs confiderably from the fixed vege- table alkali. The kind of common falt formed with this latter alkali and marine acid is called regenerated common falt, or SaLT (FEBRIFUGAL) of SYLVIUS. See that article. Fixed vegetable alkali unites alfo very well with vegetable acids, and with them forms different neutral falts, according to the nature of thefe acids. With the acid of vinegar, it makes a neutral deliquefcent falt, of a very pungent tafte, called, regenerated tartar, Or Terra foliata tartari; fee thefe words. With the concrete vegetable acid, or cream of tartar, it forms a neutral cryftallizable falt called zartarife tartar, or Salt (vegetable); which fee. "+ Laftly, fixed vegetable alkali unites alfo and forms true neutral falts with any fubftances, which, though. not pure acids, do however act as acids with relation to alkalies. Such is the fedative falt, with which this alkali forms a par-. ticular kind of Borax. See BoRAX and SaLT (SEDATIVE). Such alfo is arfenic, with which, it unites to the point of; faturation, and forms a very fingular, neutral, cryftallizable falt, the properties of which were firft obferved by M. Mac- quer, who gave it the name of neutral. arfenical falt. . See Sart (NEUTRAL ARSENICAL). | . Fixed vegetable alkali diffolves fulphur in all its fubftance; that is, it unites with both the acid and the phlogifton of. which this mineral matter is compofed. It only diminifhes the adhefion of thefe two conftituent parts of fulphur, This union of alkali with fulphur may be made in the humid way and in the dry way’; but much better in the latter. Hence refults a particular faponaceous body, called liver of [ulphur, which is a powerful folvent of all metallic fubftances. See LivER of SULPHUR. ; Metallic fubftances are capable of being attacked and diflolved by pure alkali. Some of them, fuch as iron, and, particularly copper, need only to be digefted in the liquor of alkaline falt, to be perfectly diffolved. Moft of the others: require to be previoudly diffolved by acids: but by means o this folution in acids they become very foluble in - alkali. For this purpofe it is try to pour fome drops of metallic folution into a very ftrong liquor of alkaline falt : at fy a precipitate is formed, which difappears when the Yiquor'is agitated ; thus the acid metallic folution is to be continued to. taal 2K ALT to be poured in at different times into the alkaline liquor, till this latter cannot any longer diflolve the precipitate. All metals: are not by this method diffolved with equal facility, and in equal quantities by fixed alkali. The lunar metals, namely, filver, mercury, and lead, are diffolved by it with more difficulty and in’ lefs quantity than the folar metals, fuch as gold, platina, tin, copper, and efpecially iron. This laft metal gives to the alkali while it is diffolv- ing a beautiful faffron color, approaching to red. This fo- lution of iron by alkali was firft publifhed by Stahl, and by him called martial alkaline tinlure. See TincTURE (MAR- TIAL ALKALINE) of STAHL. It is proper to obferve upon the fubject of the folubility of metals in fixed alkali; 1° That in order to its fuccefs, it is very neceflary that the previous folution of metal in an acid fhould be very acid, and very far from the point of fa- turation. In whatever manner the operation is done, it al- ways fails in making the martial alkaline tin&ure of Stahl, if a very faturated folution of iron in nitrous acid be em- ployed. © M. Macquer and Mr. Beaume have afcertained the neceflity of this management, which is not obferved by Stahl or any other chemift. 2. Mott of thefe metallic folutions in alkali preferve their limpidity only during a certain time: after which they be- come turbid, and a depofition is then formed, of the fame color as the folution. This depofition is nothing elfe than a portion of the diffolved metal which feparates from the folvent, as happens to feveral folutions of metals in acids. 3. A very illuftrious chemift recommends for the {olution of metals in fixed alkali, particularly of gold, filver, mer- cury, zinc, bifmuth, an alkali phlogifticated and fit to make Pruffian blue. But this is the precife way to fail in the operation. This able chemift has been led into error by fome of thofe circumftances, which are but too frequent in chemiftry, and againft which it is impoffible for the moft intelligent perfons to be always guarded. Some details up- oh this fubje@ may be feen under the articles BLUE (Prus- sian), and TincTURE (MARTIAL ALKALINE) o STAHL. By fufion and by the dry way, fixed alkali diflolves and vitrifies all metallic calxes, or earths deprived of phlogif- ton ; perhaps even it is capable of diffolving the metals un- calcined. Fixed vegetable alkali unites eafily with oils and oily fub- ftances, and communicates to them its property of mixing well with water. With them it forms faponaceous com pounds, AL X..A Lil pounds, partaking of the properties of oil, and of thofe of alkaline falt, as has been {aid under the article of alkali in general. See the word Soar. | As to the origin of fixed vegetable alkali, it is difputed ‘whether it exifts ready formed in vegetables previouily to their combuftion, by which it is obtained, but which in this fuppofition does only difengage fubftances which en- velope and difguife it; or whether vegetables contain only ‘the materials proper for its formation, which confequently takes place in the at of burning, and whether it be, pro- perly fpeaking, produced by fire. here are reafons for and againft thefe two opinions ; and they are fo ftrong on both fides, that there are grounds to believe that both of them are true; that is to fay, that the fixed alkali obtained after burning 2 vegetable, did partly exift ready formed in that vegetable before it was burnt, and that the other part was produced by the very act of combuftion. The proof of the former part of this propofition is, that from moft plants neutral falts whofe bafes are fixed vege- table alkali, fuch as vitriolated tartar and nitre, may be a&ually obtained without burning. And alfo, M. Beaumé, upon a particular examination of the plant called corona Jolis, found that this plant, when well cultivated, fur- nifhed not only a very confiderable quantity of perfect nitre, very fufceptible of cryftallization and detonation, the bafe of which confequently was fixed vegetable alkali, but alfo a large quantity of this alkali, difengaged from any acid, and pofleffed of all its properties. An alkali then does exift in vegetables previous to burning. It remains to be examined whether this alkali exifting in plants previous to burning, be truly one of their principles and conftituent parts, or only a foreign and unneceflary fubftance. What renders the latter opinion probable, is, that the quantity of alkali in plants, whether difengaged or united to an acid in neutral falts, is very variable, and that it appears to de- pend folely on culture and on the nature of the foil : fo that it frequently happens, that the fame plants which contain much kali when thefe two circumftances favor its introduction, contain none at all in contrary circum- ftances. As to the fecond propofition concerning the origin of fixed vegetable alkali, which is, that a great part of this alkali is produced and combined by the 2& of combuftion, it iseita- e blifhed by feveral proofs cmingly inconteftable. The ob- fervation oo "ALKALI fervation of the circumftances concurring to th i : e product “of alkali by burning, demonftrates He this alkali is in great meafure formed by the vegetable acid, which, during the deflagration of vegetables, combines in a particular Ta with a portion of their earth and inflammable prin- iple. The following obfervations will render this truth evident: _ 1. When vegetables capable of furnithing athes contain- ing much alkali, are decompofed by other means than combuftion, fcarcely any other faline matters are obtained from them but fluor acids, or elfe what are properly called effential falts, which are nothing more than concrete acids renflered ond by a portion of oil and earth. 2. When vegetables are deprived of a part of their aci by diftillation, or by extraction of their ential Gales, oo quantity of fixed alkali obtained from their afhes is lefs than it otherwife would have been in proportion to the Haaly of acid previoufly taken away. 3 e matter of extralts containing almoft all the aci of the vegetables ufed for that extraction, and the ee ed vegetables are, of all vegetable matters, thofe which urnifh the ‘greateft quantity of fixed alkali by burning in open air. The concrete acids particularly are changed by this Pikehs ne entirely into fixed alkali. A ftriking example of this is feen in the combufti i is one 3 thofe concrete acids. Elo of tree Main 4. Oils and oily concretions, which contain li i na ions, ntain little acid and. ot h, Yi after burning a fcarcely fenfible quantity "5. Plants which contain a very volati i con y volatile acid, and t fon ho » aed, obtained by it, 8) hole -fe eave alfo in their ath i le quan ; bile gly 2 8 eir athes but an almoft infen- . vegetables, even thofe which in thei fo, athes containing much fixed a Ta be after their acid has been altered by a complete putrefation, Je, afhes entirely free from alkali. ’ e cannot therefore but conclude, after havin | ttend o facts, that the greateft part of the Rone oo a a is produced from the acids’ of vegetables. 2 I: oan alfo, after what has been {aid on the origin and Pp 7 ution of fixed alkali, to perceive the reafon, why vege- able matters, which have undergone decoétions, or long ma- FE in much water, as floated wood, leave but little or no ali in their athes. The water has diffolved and carried off either eco SR rn A mss § i bgt § Ii 198 10 : gp AL RK AL 1 either the alkali ready formed, or their acids and cflential falts, which, as we. have feen, are the principal materials of its compofition. Fixed alkali prepared by the incineration of vegetable fubftances, and by lixiviating and evaporating to drynefs, is very far from the degree of purity requifite in exact chemical experiments. It is almoft always altered; 1. By fome remaining inflam- mable principle, which could not be entirely confumed during the burning; 2. By a portion of fuperabundant earth ; . By the mixture of different faline matters as fixed as itfelf, which partly or entirely elude the altion of the fire. Thefe faline matters are either fome neutral falts, which are fre- quently found in plants; {uch as vitriolated tartar, Glauber’s falt, common falt, and fometimes a little nitre; or a por- tion of fixed mineral alkali. 4. As iron is diffufed in almoft all bodies, and particularly in greater or lefs quantity in the afhes of vegetables, as Mr. Geoffroy has proved; and fur- ther, as iron is very foluble by fixed alkali; this faline fubftance is fubject to be altered by mixture with iron. " Fixed alkali may be difcovered to be phlogifticated, or altered by a fuperabundance of inflammable matter; 1. By its color not being perfectly white, and by its lixivium or {olution in water being more or lefs yellow, or red inftead of being abfolutely colorlefs; 2. By the fmell of its lixivium, which is always fo much ftronger, as it is more phlogifticated ; 3. By its degree of cautticity, which is always fo much lefs 2s it retains more fuperabundant inflammable matter ; 4. Laftly, by its property of forming Pruffian blue, by pre- "cipitating folutions of iron in acids, when it is much phlogif- ticated. See upon this lal article, BLUE (PRUSSIAN). There are two methods of purifying fixed alkali thus altered, that is, of depriving it of all the fuperabundant inflammable matter it contains. The firft is by calcination, according to the general rules and with all the attentions neceffary to be obferved in calcining by fire. See CaLciNa- TION. The fecond method of purifying fixed alkali from fuper- abundant inflammable matter confifts in applying to it a body on which it cannot a&, and which has a ftronger affinity than it with this inflammable matter. M. Beaumé firft pra&ifed this fecond method. This able obferver, having perceived, that when he evaporated in filver veflels red and phlogifticated alkaline lixiviums, thefe veflels were more and more tarnifhed, till at length the furface of the filver AL RX AL 1 filver became quite black, and that the lixivium loft its color in proportion as the filver acquired it, carried this experiment as far as poffible; and at length, by renewin the furface of the filver contiguous to the alkaline rs he deprived this lixivium of all its color, and rendered it anarely white. This lixivium being then evaporated to drynefs, furnifhed an alkali very white, very cauftic, and free from all fuperabundant phlogifton. Befides the practical method of dephlogifticating alkaline falt, which this expe- riment fuggefts, it alfo confirms a truth demonftrated b M. Macquer in his theory of Pruffian blue; namely 4A metallic fubftances may be charged with a fuperabundant Quipisy of a ye and that they are capable of taking it from fixed alkali b i (pve gh y the humid way. See BLug he fecond fubftance which alters fixed alkali i - abundant earth. As this earthy fubftance is ER water when alone, and as it has but a weak adhefion to the alkali, it may be eafily feparated by drying it once or twice by folutions and filtrations. But this purification muft not be carried too far, becaufe the alkali itfelf is capable of decompofition by this method, for at every drying or calci- nation, a part of its earthy principle is difengaged. As to the faline matters which by their mixture alter the purity of the fixed alkali, they can be feparated by no chemical procefs but by cryftallization. This method is founded on the incapacity of the alkaline falt to cryftallize and on its property of decompofing and of converting into cryftallizable falts all uncryftallizable and dig utn falts with which it may be mixed. It is then neceflary to evaporate, as much as is convenient, the alkaline liquor oa which thefe igen falts are to be feparated, and to let it cool at feveral different times to favor the cryiftallization of thofe falts which are beft cryftallized in the cold, or to continue the evaporation for thofe falts which, like common falt, can only be cryftallized by this method. See Cry- JrauzATION, But it is manifeft, that this method owever carefully performed, is incapable of procurin a perfect feparation of all the extraneous falts from the alkali 3 for, while the alkali continues fluid, it always remains mixed yi 3 {niall quantity of cryftallizable falts, which are dif- fb ie by part of the fame water which keeps the alkali Bs 3 and therefore the feparation by cryftallizafion cannot ake place when all is evaporated to drynefs. - It is im- ly to feparate completely from the alkaline falt, the or. I. F ’ aft A SE — a i | | |] | | | | i | i ! t ALXRRALA] faft fmall portions of extrancous falts with which it was mixed. Notwithftanding this, the degree of purity to which the alkaline falt may be brought by this method is confiderable, and fufficient for moft of the operations of the arts, and even for many operations in chemiftry. = It is {till more difficult to purify the alkali from iron. No pra&ical method is known for this purpofe. When therefore a very pure alkali is required, it is proper to choofe fuch fubftances as furnifh a falt the leaft impure. For in this refpect there is a great difference betwixt the fubftances from which it may be obtained, as will appear when we enumerate fummanily the feveral alkalies moft frequently ufed. Fixed alkali being of great ufe, and much employed in arts, as it is the bafis of foap and leys, and much ufed in dying, making of glafs and faltpetre, 1s procured from matters which furnifh a great deal of it, and at a fmall rhe moft common alkali, and at the fame time the leaft pure, is that of the afhes of common hearths. Thefe afhes are employed for lixiviums, in the manufacture of faltpetre, and in glafs-houfes where common bottle-glafs is made. In the Northern countries, where Yh 1S pleut is nt on purpofe, as well as many plants, to procure from ela bl a Ron but very impure alkali, called Pot-afh. This .alkali is always much phlogifticated, and contains many of the faline matters above-mentioned. Pot-ath is mploved for the purpofes related. It is alfo ufed by dyers y 1A of their operations. Pot-afh may be purified fo far § as to become a very good alkali by the methods men- § The (8 tioned. (¢) (6) In fome parts of Germany Pot-ath is prepared from the § fre wood of which charcoal is made. A number of tubes, made 8 of plate iron, or of copper or brafs, are fo difpofed in the pile of § wood intended to be burnt into charcoal, that the water, acid, 3 and oil, which are obtained in the ordinary method of diftilling i wood, fall, when feparated from the wood by fire, pafs through § thefe tubes into buckets placed to receive thefe liquors. The oil i is then to be feparated from the acid liquor, which is flenvigrds 3 to be boiled in copper or iron veffels, and the refiduum dried an 1 calcined. By this calcination, the acid falt is alkalized. This procefs, and the preparation of falt of tartar by calcining tartar, §8 thew that vegetable alkali is produced by converfion of an acid to a The 3 an alkali. How is this converfion effeéted ? | ALXKALZX The dregs and leys of wine being dried and burnt, leave afhes abounding in alkaline falt, called in French, cendre gravelée. 'The moft common method of making pot-afh, is by burning large piles of wood, lixiviating the athes by boiling in copper veflels, decanting the lixivium when clear, and boiling it in other copper veflels till the liquor be evaporated and a reddith folid falt obtained, called é/ack pot-ajb, which by calcination in ovens with a heat not intenfe enough to fufe it, is dephlogifticated and ren- dered white, If any of it has been fufed, it will have a greenifh blue color. Another method of preparing pot-ath, and which may be con veniently ufed in a large manufalory of it, is defcribed by Kunckel. The afhes of wood are put into a large tub, near the bottom of which is inferted a cock ; and to prevent the athes from filling up the cock, the bottom is covered with ftraw and pieces of {mall wood. Water is to be poured on the afhes, and is the next day to be let off through the cock into another veflel. The athes may again be elixated with more water till all the falt be difiolved. The weaker leys are to be poured on freth parcels of athes till they can receive no more falt. The ley is then to be evaporated in an iron pan, and the brown falt is to be dephlogif- ticated by calcination in a furnace or oven with a heat not intenfe enough to fufe it.----Some perfons foak ftraw in the ley obtained by lixiviating wood-athes with water, and by drying and burning this ftraw they obtain a falt without the trouble of boiling the ley. The Ruffia pot-ath is dark-colored, hard, not eafily deliquefcible, and contains (as Dr. Lewis fays) more than half its weight of an earth unfoluble in water. Scheffer, in the Swedith Memoirs for the Year 1759, fays, that from 100lb. of Ruffian pot-ath he obe tained ¢2! 1b. of alkaline falt, and 911b. of neutral falts. Dr. Home found that Ruffian pot-ath contained a confiderable quanti- ty of quicklime. From experiments made by Brandt ( Memoires Suedoifes 1749), and from the preference given to it by foap- boilers, it appears to be more cauftic, and more powerfully to diffolve oils, than purer pot-afth rendered cauttic by quicklime. Ruffian pot-ath is faid to be prepared by burning wood with a clofe {mothering heat; making a ley from the coarfer part of the afhes, and moiftening therewith the finer part into the confiftence of a pafte, ftratifying this pafte with fome of the more inflam- mable kinds of wood, and fetting the pile on fire. ‘The neutral falts found in pot-ath are chiefly vitriolated tartar, fea-falt, with Which latter falt pot-afh is frequently adulterated to increafe its weight, ‘I'he afhes of firs, pines, and all trees which contain much refin and effential oil, yield a fmall quantity only of fixed alkali by elixation. The caufe of this feems to be, that the acid of thefe Fa trees ALXKALL3Z} gravelée. This alkali is not only in great quantity in thefe afhes, but likewife when the matters furnithing it are pros perly and carefully burnt, it is the pureft of all thofe which are in commerce. If it contains iron, the quantity of this metal is fcarcely fenfible ; and it is naturally free from mix- ture of extraneous falts : therefore dyers and other manufac- turers, whofe operations require a pure alkali, prefer thefe to any other alkaline afhes. Fixep ALKALI of TARTAR. TARTAR, which is nothing but the concrete acid or eflential falt of wine, being properly burnt, is almoft entirely changed into an alkaline falt, very ftrong, and the pureft of all; and which therefore has been reafonably preferred by chemifts to any other. It is called the Alkaline Salt of Tartar, or fimply Salt of Tartar. Hence this name has become in fome meafure fynonimous with that of alkali. Salt of tartar is made by wrapping up in wet brown paper the tartar intended to be burnt, and placing thefe parcels fo wrapped up in a furnace, in beds or ftrata, together with ftrata of charcoal, alternately ; and by fetting fire to the whole, and continuing the fire till no more blackening fmoak arifes. As tartar is almoft entirely changed into alkaline falt, it preferves after incineration a certain confiftence, and retains the form it had before burning; which makes it eafy to collect it properly. But too great heat muft be prevented in burning tartar, otherwife the alkali would melt and flow to the bottom of the furnace, where it would mix with the impurities of the charcoal. To avoid this inconvenience a furnace entirely open may be employed, in which the charcoal may burn freely, but without any ftrong current of air to render the heat too intenfe. On the other fide, as fire is generally more intenfe in great than in {mall opera- tions, where proportionable quantities of combuitible matters are ufed, when much tartar is to be burnt, it is proper to diminifh the quantity of charcoal, to prevent too great heat, and the confequent fufion of the alkali. trees is very volatile, and together with a volatile inflammable matter forms the effential oils and refins. Sez Resins. Plants that are auftere, acid, bitter, or aromatic, Jel by incineration the largeft quantity of alkali. Rotten, dry, and old plants, burn with little flame, and yield little alkali. 3 When ALKALI When tartar is fufficiently burnt, a lixivium muft be made from it till the water poured on it rcceives no more tafte. It muft then be filtered, evaporated, dried and cal- cined, according to the directions given to obtain the alkali of tartar in its greateft purity, Fixep ALKALI of NITRE. THE bafis of nitre being a fixed alkaline falt of the nature of the vegetable alkali, and the acid of this falt being capable of decompofition and total deftruttion by deflagration, we may obtain feparately its alkali, called alkalifed or fixed nitre, by burning or detonating rt with combuftible matters. As this combuition is very rapid, and as it is alkalifed almoft inftantaneoufly by detonation, it has been alfo called extem= poraneous alkali. The matters moft convenient and moft frequently ufed © for the deflagration of nitre are charcoal and tartar. The alkali made by deflagration of nitre with charcoal is called NiTRE fixed by CHARCOAL. See this article for the method requifite. itre and tartar burnt together produce a very ftrong alkali, which is a mixture of the alkali of nitre and of the alkali of tartar, both which are entirely of the fame nature. They are confounded together by the name N1TRE fixed by TARTAR. See that article, and FLux (WHITE). Thefe alkalies of nitre, when well prepared, are very pure, and fit for the niceft operations in chemiftry. All thefe feveral kinds of alkali, when perfectly purified, have entirely the fame properties, and ought to be regarded only as one and the fame alkali, which ought to be called Fixed Vegetable Alkali. The purification above-mentioned of this alkali is attended with confiderable difficulties in practice. The chief of thefe difficulties isin the evaporation and drying of the alkaline lixiviums ; and this relates to the veflels employed in thefe operations. Veflels made with the imperfect metals are unfit, becaufe they are liable to the action of the alkaline falt. Silver veflels are the fitteft of all for this purpofe ; but it is not very certain that this metal is incapable of being acted upon by alkali. Glazed earthen veflels, fuch as common pottery-ware, cannot be employed, becaufe they are not, and cannot be fufficiently baked. The alkaline lixivium paffes through them as eafily as through a filter. If veflels not metallic are ta be ufed, they ought to 2 of glafs or porcelaine, or made 3 of AL RAL of pure clay, and baked in a violent fire, fuch as that kind of pottery called ftone-ware, Thefe veflels perfectly refift the action of alkalies, but they are very liable to be cracked by heat. Well-prepared fixed alkali ought to be preferved, either dry or fluid, in cryftal-glafs bottles, with glafs ftoppers. When the fluid alkali is ufed, it muft be gently decanted from the fediment depofited at the bottom of the bottles. ALKALI (MINERAL or FOSSILE), or AL- KALI (MARINE). This is a faline, alkaline, fixed {ubitance, ferving as a bafis to the acid of common falt, and forming with it the native neutral falt which is diffolved in large quantities in the fea, and known by the names Cominon Salt and Sea-Salt. As this falt is a natural production, and belongs neither to the vegetable nor animal kingdoms, it has been ranged amongft minerals, and therefore called mineral alkali: notwithftanding that a confiderable quantity of this falt may be obtained from the afhes of feyeral vege- tables. But its origin is always the fame, and it is not ta be confidered a vegetable fubftance; for we fhall fee that mineral alkali obtained from vegetables, proceeds ‘always from common falt contained in thefe vegetables. After we have mentioned the properties of this alkali, we fhall defcribe the method of procuring it in its greateft purity. Fixed mineral alkali has eflentially and fundamentally all the properties of fixed vegetable alkali. It has the fame tafte and the fame fixity. It diffolves all the fame fubftances, and exhibits with them very fimilar phenomena. It melts and vitrifies all earths, and 1s altered by quicklime in the fame manner. It combines with all acids to the point of faturation, and with them forms neutral falts. It has the fame ‘action as fixed vegetable alkali on metallic fubftances, and forms foaps with oils and oily matters ; therefore, in order to have a juft idea of the alkaline properties of this faline. fubftance, it is very neceflary to read carefully and entirely what has been faid under the articles ALKALI and Arkarl (Fixgp VecerasiLe). But it alfo differs very confiderably from fixed vegetable alkali by feveral properties peculiar to'it; and it is upon thefe properties we are chiefly to infift in this article. Fixed mineral alkali, which we here fuppofe to be in its greateft purity, differs from fixed vegetable alkali, 1. By its tafte, which is a little lefs fiery and corrofive : but this difference is very flight. ALKATLI dried, it does not attra& the moifture of the air livin NA a liquid, as fixed vegetable Ahaliay 3 If it be diffolved in atts) hea it N dry and calcined, i ater nearly io much, * do Hine in and its folution evaporated and cooled, it coagulates into cryftals, precifely as heutry falts do. In this it differs confiderably from fixed veges] le alkali; which is abfolutely deliquefcent, and not cryltal- zal os of mineral alkali contain much goto) have but little adhefion to this water 5 for moft of it 3 iffi- pated by expofure to open air. By this diffipatien of trains the cryftals lofe their form and tranfparency, Wa oe owing, as of all neutral falts, to the water contained. o¢ ZATION: vials of miseral alkali thus deprived of their water, 4 into a white powder : Sherer to preferye hens they mult into bottles as foon as they are drained. Be erences related re the vegetable and mineral alkalis thew that this latter poflefles faline properties in a lefs eminent degree; which probably proceeds from the its earthy principle. tS diss albali Jiffotves by fufion, and vitrifies ot earths like the vegetable alkali, But it has been obferved, that it vitrifies earths better, and renders the glafs more folid and durable, Probably this proceeds from the greater fixity of the mineral alkali, from its containing an gis lefs combined, and alfo from its want of the deliquefcent ith vitriolic acid, mineral alkali forms a neutral cryftallizable falt called Glauber’s Salt, which differs from vitriolated tartar in the following circum{tances. L : ts cryftals are of a different figure and larger fize, 2. They contain more water, 3. | hey are more foluble in water, 4. Their adhefion to the water of their cryftallization is lefs, infomuch that this falt by expofure to air lofes 3 water, and confequently its form and tranfparency, es becomes a white powder, as the mineral alkali does : o when expofed to air. Sez SALT of GLAUBER. As the iy acid is in Glauber’s falt and in vitriolated tartar, the di . ferences above related muft proceed from their alkaline 1 i hat #) We have obferved in a note upon the former article, t I rete alkali is cryftallizable by expofure to {everal kinds of gas. Fa bafes : ALKALI bafes: therefore all the properties which diftinguith Glau- ber’s falt from vitriolated tartar are to be confidered as the differences betwixt the vegetable and mineral alkalis. The fame obfervation may be applied to all combinations of . mineral alkali with the other acids, of which we are now going to fpeak. 9. With nitrous acid, mineral alkali forms a particular kind of nitre, fufceptible of detonation and of cryftalliza- tion; but it differs from ordinary nitre, or that which has for its bafe fixed vegetable alkali, in the figure of its cryftals, which, inftead of being like long needles, are folids, each of which has fix rhomboidal faces; that is to fay, two angles of each face are acute, and the other two obtufe. ‘This figure, which is fomewhat fimilar to that of a cube, has occafioned this falt to be called cubic or quadrangular nitre. This figure is caufed by the mineral alkali. Se NITRE (QuADRANGULAR). | 8. With marine acid, mineral alkali forms common fale, the cryftals of which are perfeét cubes. This fale differs from the neutral falt formed by the combination of the fame acid with vegetable alkali chiefly by its tafte, which is in- finitely more agreeable. See Sart ( Common). 9- Mineral alkali forms with the acid of vinegar a neutral falt entirely different from the terra foliata tartari, which is deliquefcent and not cryftallizable, while the former cry- ftallizes well, and does not attra& the moifture of the air. This falt has no particular name. See Sart (NEUTRAL) €Compofed of the ACID of VINEGAR and of MunERAL AL- KALIL 10. With the concrete tartareous acid, mineral alkali forms a neutral cryftallizable falt, differing from that made with the fame acid and vegetable alkali, or vegetable falt, by the figure of its cryftals, which are alfo much larger and finer. This faltis called Salt of Saignette. See Sart of SAIGNETTE. 11. Mineral alkali very well diffolves oils and oily matters, and with them farms faponaceous compounds, as the vege- table alkali does. But foaps made with this latter alkali re- main foft, and do not acquire fuch confiftency and hardnefs as thofe made with mineral alkali. This difference is certainly caufed by the property which mineral alkali has of cryftal- lizing, "See Soar. (1) | It ¢2) The difference mentioned in the text does certainly not proceed from the cryftallizing quality of mineral alkali; for this {alt ALKALI It is probable, that if we were to examine attentively the eombinations of marine alkali with fulphur and metallic fubftances, fenfible differences might be difcovered from fimilar combinations made with vegetable alkali. The dif- covery of thefe differences could not fail to throw new light upon the nature of this alkali. But I do not believe that fufficient experiments have been made on this fubje&. (m) Several celebrated chemifts have, however, made con- fiderable refearches into the nature of marine alkali. The ron who has done moft in this way is M. Duhamel de a a member of the Academy of Sciences. He has publifhed in feveral memoirs, a detail of many experiments made to decompofe common falt, that he might obtain the alkaline bafis fingle and pure, for the purpofe of examining its properties. es falt not being capable of decom- pofition merely by the action of. fire, and without the application of another fubftance, it was neceflary to find fome fubftance which could carry off the marine acid, with- out combining itfelf with the alkaline bafis. As phlogifton produces this effect very well on thofe neutral falts which are compofed of a fixed alkali and vitriolic or nitrous acids, it was natural to try the feparation of the marine acid by the fame intermediate’ fubftance. This M. Duhamel did, but without fuccefs; although in his experiment he employed every refource of the moft enlightened chemiftry. The fame thing happened to Mr. Margraaf, who tried without fuccefs to combine marine acid with phlogifton, in order to produce phofphorus. It appears, then, that art does not yet furnifh any method of decompofing common falt by phlogifton. It is neverthelefs probable that this decompofition is not impoffible, and that it even takes place every day in the combuftion of maritime plants of the 4a/i kind, all of which contain fea-falt, and when burnt, furnith a confiderable quantity of cryftallizable alkali, which being combined with falt cannot be formed into a hard foap till it has been deprived of its cryftallizing quality by quicklime, which, by abforbing its gas, renders it cauftic, and incapable of forming cryftals. See Gas. The greater hardnefs of foaps made with mineral alkali than of thofe made with vegetable alkali, probably proceeds from that property of mineral alkali by which it has a weaker power of combination with water than vegetable alkali has. (m) A remarkable difference has been obferved by Margraaf between the mineral and vegetable alkalies ; namely, that pla- tina may be precipitated from its {olution in aqua regia by the latter, but not by the former. 4 the HL IRs meee ——————————————————— aca a—— ALE ARK: the vitriolic and nitrous acids forms Glauber’s falt and cubic nitre, entirely fimilar to thofe formed from the decompoii~ tion of common falt by thefe two acids. It is very probable that this cryftallizaple alkali obtained from the afhes of maritime plants, proceeds from a portion of fea-falt con- tained naturally in thefe plants, a part of which is decom- pofed by the burning ; for it is certain that no trace of a difengaged alkali can be obferved in thefe plants previoufly to their incineration. : However that be, it is certain that this cryftallizable alkali obtained from the afhes of maritime plants, is entirely of the fame nature as the natural alkaline bafis of fea-falt. This is a truth which no chemift queftions. But difputes have arifen concerning the faline alkaline nature of this {ub- ftance. The inquiries of M. Duhamel had proved to him, that it had the principal marks of a faline alkali; he concluded that it really was fuch. On the contrary, the celebrated Mr. Pott, who has alfo made many experiments on this matter, has always maintained that it was only a pure earth, with- out the properties of an alkaline falt, This diverfity of fentiments has occafioned a literary difcuffion betwixt thefe two learned gentlemen, of that kind which always turns out to the advantage of fcience; 2s it has occafioned ‘a great number of beautiful experiments, which greatly illuftrate this matter. ; The ftrongeft proof brought by Mr, Pott in fupport of his opinion, may be found in the Eclairciflements given to the fequel of the French tranflation of his Lithogeognofia, Mr. Pott fays, ¢ that bya fixed or volatile alkali an infipid « and perfeétly infoluble earth may be precipitated from ¢¢ the mother water of fea-falt, This earth. united to the « vitriolic acid- forms a Glauber’s falt perfectly fimilar to « that prepared from fea-fait. This Glauber’s fzlt produces « with charcoal a faline alkaline body, which is not preci- « pitable by fixed vegetable alkali; which alfo happens « precifely to Glauber’s falt prepared with fea-falt. This « alkaline falt is not produced by the vitriolic acid, nor by « the charcoal, -but principally from this faline earth, « which for that reafon may be called an alkaline earth, ¢¢ nearly approaching a faline ftate, and which is capable ¢¢ of taking from acids a proper portion of their moft fubtle ¢¢ parts, by combination with which it becomes a genuine ¢¢ alkali,” mr ALKALI As to what remains, it appears that, after the properties - of fixed alkaline falts and of the bafis of fea-falt have been eftablithed, it is eafy to decide the queftion. Nothing can be faid more fenfibly on this fubject than the following quo- tration from the learned and judigious tranflator of Mr. Potts Lithogeognofia. ¢¢ This queftion is now reduced to «¢ a difpute about words, fince Mr. Duhamel agrees with «¢ Mr. Pott, that the bafis of fea-falt differs from the fixed «¢ alkali of nitre and others fimilar; and that -Mr. Pott < agrees with Mr. Duhamel, that it differs from common <¢ abforbent earths. But hitherto it feems that Mr. Duha- ¢ mel’s expreffion is more juft and conformable to the de~ «¢ finition of faline {ubftances.” ’ From all this we ought to conclude, that the bafis of fea- falt is neither a pure earth, nor an alkali fimilar to that obtained from vegetables, but a faline alkaline fubftance of a peculiar nature; and if conjectures may be allowed on the nature of this alkali, I fhould be inclined to believe, that it differs from the vegetable alkali, either becaufe a larger quantity of earth enters into its compofition, or be- caufe its earthy principle is united to it more intimately. Further, it appears that the bafis of common falt is truly of a faline nature, from its fuccefsful and even advantage- ous application to all the fame purpofts in the arts as fixed vegetable alkali, as has been faid above. The only practical method of procuring this alkali in great quantities is by the incineration of maritime plants. Thefe athes contain much mineral alkali, when the plants happen to grow in a favorable foil and climate, and the mi- neral alkali is found to be more or lefs pure, according to the nature of the plants and of the foil. Thefc athes are generally known in commerce by the name Soda. ‘This foda is employed in arts without purification ; hence there is obferved a great difference betwixt different fodas, fome of which are much better than others. (7) As (2) Mineral alkali is found lying upon the ground in the ifland of Tenerif, and in many other countries. The Spanith athes called lariglia, or joda, are produced by burning kali, and perhaps fome other maritime plants, previoufly dried, in pits dug in the ground. From thefe plants Henckel obtained, by boiling in water, evaporating and cryftallizing, a confiderable quantity of marine falt. Stahl, Gellert, and other authors, pre- fer this falt to vegetable alkali, for the formation of glafs, which they ee ee en og ” ALR ANLIE As the chemical affinities and the medicinal virtues of the mineral and of the vegetable alkalis are the fame, we pro- ceed to mention what is moft material on thefe fubjects. The affinities of fixed alkali, according to Mr. Geoftroy’s Table, are in the following order : vitriolic acid, nitrous acid, marine acid, vinegar, fulphur. Mr. Gellert’s Table is more extenfive, and is as follows : Phlogifton, vitriolic acid, nitrous acid, marine acid, vege- table acid, zinc, iron, copper, lead, tin, regulus of anti- mony, regulus of cobalt, arfenic and bifmuth. Gold and filver are marked in this Table as indiffoluble by fixed alkali. As fixed alkalis are the greateft abforbents of acids, they are proper for all thofe maladies defcribed by Boerhaave as proceeding from a fpontaneous acid. They are even pre- ferable to abforbent earths, (although thefe latter are more frequently ufed) in cafes where, notwithftanding figns of acidity, a putrefcent difpofition is apprehended ; which is not at all impoffible, becaufe they are, like all faline mat- ters, antifeptic, according to the obfervations of Dr. Prin- gle. But if the putridity was advanced to alkalefcency, which is very rare, they would be very hurtful, becaufe they would increafe this alkaline acrimony. ¢ muft not be fuppofed that fixed alkalis taken internal ly, enter the blood-veffels with their alkaline qualities. If that happened, they would be true poifons, as acids are; fince they quickly kill animals into whofe veins they are injected. | The human conftitution, which cannot {fuffer the pre- fence of any fenfible and difengaged acids or alkalis, at leat to a certain degree, in our fluids, acts upon alkalis taken internally by combining them in digeftion with the acids of aliments, or with their oily parts, forming foaps, in which conditions only they can arrive at the blood. Pure alkalis ought never to be prefcribed but in fmall dofes, as from half a grain to two grains, when they are they pretend it makes more durabl= and lefs liable to be attacked by acids. But Kunckel obferves, that the impurities mixed with common foda, or bariglia, give a bluifh color to glafs, and ren- der it liable to crack, when cooled. Stahl obferves, that the fame effet is produced by common pot-afh. I have obferved Ne that every kind of fixed alkali, however well refined, gives a blue caft to glafs, which requires to be corre&ted by Manganefe. The mineral alkali, as has been obferved in the text, makes a finer, harder foap than vegetable alkali. It is alfo faid to be more effe®ual in the reduction of metallic calxes. : incorporated ALKALI incorporated with folid medicines and in fmall bulk ; but they may be given from one to fix grains, if they be diluted, on account of their caufticity, in a pint of fome watery ve= hicle. Thefe faline fubftances are diffolving, aperitive, and lithontriptic. They are not much employed for thefe qua- lities ; but are principally ufed to correct refinous purga- tives, which they do very well, by giving to thefe medicines a faponaceous quality. Externally applied, thefe alkalis are refolvent, difcutient, and cauftic. (0) ALKALI (VOLATILE). Volatile alkali is 2 faline fubftance procured by decompofition, from all ani- mal, and from fome vegetable fubftances, and by putrefac- tion from all thefe matters. (p) (0) Dr. Smith, in a treatife de mofu mafculari, relates an extraordinary fa&, which he affirms to have afcertained by repeat- ed experiments, namely, that of the many fubftances which he mentions, acid, alkaline, and corrofive, mineral alkali and compounds formed of it were alone capable of ftimulating or ir- ritating the mufcles of frogs, by immediate application to thefe mufcles, which were expofed for the fake of making thefe expe- riments. (#) The plants from which volatile alkali is obtainable by diftillation are chiefly of the cruciform kind. This alkali is ob- tained by diftilling all kinds of clays, (as Brandt fays) many cal- careous earths, chiefly that kind called Lapis fuillus, and fome mineral waters. Sal ammoniac, which contains volatile alkali, is fublimed in volcanos. Sal ammoniac may be produced from foots of burning vegetable or animal fubftances, and even of mi- neral coals. Authors mention various methods by which volatile alkali may be produced. Asa knowledge of thefe may aflift us to form a theory concerning this faline f{ubftance, we fhall relate fome of them. Volatile alkali may be produced by heat, 1. From a mixture of quicklime with vitriol, or with alum, or with tartar. Port, 2. From a mixture of any effential oil with vitrio- lic acid and fixed alkali. 74. 3. From nitre detonating with charcoal. Jd. 4. Froma combination of marine acid with quick- lime. Jd. 5. From magnefia alba by diftillation, Dr. Black. 6. From tartar. Id. 7. From deliquiated falt of tartar poured on, white falt of vinegar, German Ephemerides, Pott, Ludowici, and Hoffman. ¢. From fea-falt combined with putrifying fubitances. Pott. 10. From fea-falt diftilled with charcoal. Id. 11. From fea-falt diftilled with quicklime. Jd. 12. From falt of Sylvius diftilled with fixed alkali. Beck and Peterman. 13. From fea-falt diftilled with clay. Brandt, 14. From ruft of iron diftilled. Bourdelin, This | | | | | i : : ; J] hl | : id +1 at: Hi [RE 4 AR | I) hi 1 $i HEE iH ! fh IH Hi | { igs i | - 1 t {1 | | ti EL 1} I LY | { Aa io Hg tl it SLT] il | IH | | ¥ A-L KA L4 This faline fubftance is called alkali, becaufe in’ fad if has all the general properties of faline alkalis, as the fharp, cauftic and burning tafte ; the property of tinging violets with a green color ; of combining with acids to the point of faturation, and forming with them different neutral fats, _ moft of which are cryftallizable ; of feparating all earthy and metallic matters from their union with acids ; laftly, of diffolving by the humid way, almoft all fubftances folu- ble by other alkalis. Li Ji This alkali is called wolatile, becaufe in fal it is very much fo. Its volatility is owing to a portion of attenuated, very fubtle, and very volatile. oil, which enters into. 1ts compofition as one of its principles, as 15 proved by its diftinguifhing properties. Volatile alkali differs according to the fubftances ‘whence jt is procured, and according to the manner of obtaining it. Thefe differences proceed from fome principles fuperabun- dant and extraneous ; particularly, feveral oils from which it is not at firft exactly depurated. But all volatile alkalis, however obtained, and from whatever fubftances, may be fo purified by the method which fhall be foon defcribed, that no difference remains amongft them ; and hence we ought to conclude of this fubftance, as well as we did of the various kinds of fixed alkali, that 1t is fingle, identical, and always fimilar to itfelf, when fufficiently purified. i Pure volatile alkali differs from fixed alkali, firft, by its greater volatility, which is fo great that it may be entirely fublimed or diffipated by a heat much lefs than the heat of boiling water ; by its fmell, which is only an effect of its volatility : the fmell of this falt is trong, very penetrating, and fo pungent, that it cannot be endured above an inftant, without fuffocation or fainting ; its vapor excites a cough, and brings tears into the eyes. {tis his falt which occafions the pungent fmell obferved in neceflary-houfes at changes of weather. - : This alkali differs alfo from the fixed by its lefs force ; hence fixed alkalis are capable of decompofing all tho'e falts whofe bafes are volatile alkali, of feparating It from thefe falts, and of fetting it at liberty. Ly Volatile alkali unites perfectly with water, to which it has even a ftrong affinity, and with it retains fluidity ; 1t 1 then called volatile alkaline fpirit. When it contains no fuperabundant water, it is in a concrete form, and is 3 cryftal- AL RIA LA sryftallized, in which it differs from fixed vegetable als kali. (¢) All ‘acids unite and effervefce with volatile alkali to the point of faturation, forming neutral falts, generally called ammoniacal falts. Ammoniacal falts have an infinitely ftronger and more pungent tafte than falts whofe bafes are fixed alkali, becaufe volatile alkali unites with acids lefs intimately. ‘Thefe neutral falts are femi-volatile ; that is, they may be fublim- ed by a fufficiently ftrong heat ; and this property they owe to the volatility of their alkaline bafis. : The ammeoniacal falt which volatile alkali forms with vitriolic acid is cryftallizable, and is called witriolic ammo niacal falt, or fecret ammuniacal falt of Glauber,. from the name of the chemift who difcovered it. See thefe words. The kind of nitre formed by volatile alkali and nitrous acid is alfo cryftallizable, and has the peculiar property of detonating alone, when heated fufficiently, -without ad- dition of any matter containing phlogifton,” as 1s necefiary for the detonation of ordinary nitre. This phenomenon proves the exiftence of the inflammable principle in vola- tile alkali. ‘This nitre, whofe bafis is volatile alkali, is called ammoniacal-nitre, or nitrous ammoniacal falt. See thefe words. With marine acid, volatile alkali forms alfo a neutral cryftallizable falt, called Sa! Ammoniac. ‘This is the moft ufed, and firft known of the ammoniacal falts, and from which the name has been derived to the others. See SAL AMMONIAC. Volatile alkali may be combined with fulphur, with which it forms a kind of volatile liver of fulphur, the pre- paration of which is given by Hoffman. See Liver of SULPHUR. Moft- metallic matters are attacked, and more or lefs diffolved by volatile alkali; but copper is of all metals the moft eafily and copioufly diffolved by it. To diffolve this metal, nothing more is requifite than to digeft its filings in liquid volatile alkali. The folution acquires a beautiful blue color. This folution exhibits a curious and interefting pheno- menon, which is, that if the bottle containing it be well _ (g) Volatile alkali, by combination with gas or fixable air, is cryftallizable ; uncombined, it cannot be obtained in a folid ftate, corked, ALE:a Ld éorked, the blue color grows fainter, and at length entirely difappears, fo that the liquor becomes colorlefs like water. But if the fame bottle be then uncorked, the upper part of the folution from its contact with the external air re- fumes its color, and this color is gradually communicated to the reft of the liquor. Thus may this blue color be made to appear and difappear alternately, as often as is re~ quired, by corking and uncorking the ottle. Other metallic matters are not nearly fo eafily attacked by volatile alkali as copper is. Thefe folutions have even not been much examined. a ; When metals are previoufly diffolved and divided by acids, they are then infinitely more fufceptible of folution by volatile alkali. For this purpofe it is fufficient to pour into fome ftrong alkaline fpirit fome drops of metallic folu- tion. At firft a precipitate is formed, which foon difap- pears upon agitating the liquor, and is rediffolved by the volatile alkali. ‘That this experiment fhould fucceed, it is neceflary that the metallic folution fhould have a con- fiderable excefs of acid; that is, that the acid fhould not be nearly faturated with the metal. By this method, cop- per and mercury are diffolved in greater quantity than other metals. : In whatever manner the copper be diffolved by this falt, it always communicates a blue color, very beautiful and deep. ‘This property renders the alkaline fpirit a proof liquor to difcover copper, and render it fenfible when it could not, from the fmallnefs of its quantity, be percepti- ble by other methods. Thusa little volatile alkali may be poured into any mineral water, containing too {mall a quantity of copper to be otherwife perceptible. The blue color which this water affumes difcovers the prefence of copper. Volatile alkali, added gradually to 2 metallic folution, {eizes the acid of the folution, and precipitates the metal. The moft fingular metallic precipitate made by volatile al- kali is that of gold previoufly diffolved in aqua regia. This precipitate is of a yellow color, and is one fourth part heavier than the gol employed. When heated to a certain degree, it detonates and fulminates with a moft terrible explofion. It is called fulminating gold. See GoLp (FULMINATING). oo co Mercury diffolved in {pirit of nitre, and precipitated by volatile alkali, is of a {lite color. This color proceeds from the inflammable matter of the volatile alkali. The other metallic ALKALI metallic precipitates made by volatile alkali have nothing fingular : none of them fulminates like the precipitate of gold ; even that of platina does not, ‘though this metal poflefles fo many of the properties of gold. (7) Volatile alkali, as well as fixed, ats upon oils, and forms with them different faponaceous compounds ; hence this falt may be employed to {cour and clean from greale 5 and lixiviums made of quicklime and urine, which contain much volatile alkali, are ufed in fome arts. This alkali is, however, lefs eafily united with oils’ than fixed alkali is, and particular management is neceflary to bring it to a fapomaceous ftate. See SPIRIT (VOLATILE AROMATIC Oi1Ly) ; and Eau pE Luck. Thefe are the principal fapo- naceous compounds made with volatile alkali. Volatile alkali, when firft feparated from animal and ve- getable matters, is, as we before obferved, very impure. It is particularly depraved by much empyreumatic oil, which is united with it into a ftate perfectly faponaceous, and which it renders foluble in water. It may be fepara- ted from this fuperfluous oil by diftilling it with a very gentle fire, either alone, or mixing with matters capable of abforbing and retaining the oil, as fixed alkalis and ab- forbent earths are. But the moft efficacious method of purifying it is, to reduce it to fal ammoniac, and then to decompofe this falt, by any of the proper mediums for the difengagement of the volatile alkali. By this method it is obtained in its greateft purity ; becaufe, in its combination with the acid, it perfectly feparates itfelf from all extrane- Yr) From Mr. Margraaf’s Experiments, publifhed in the Berlin Memoirs for the year 1745, we find that gold, filver, bifmuth, zinc, and copper, diflolved in their proper acid folvents, may be firft precipitated from thefe, and afterwards redifiolved by volatile alkali; that thefe metals precipitated by fixed alkalis may be again diflolved by volatile alkali; and that mercury, lead, and tin, were not diflolved by volatile alkali applie. in the fame manner. - Brandt fays, that volatile alkali occafions a coagu- lation of a folution of iron in nitrous acid, which is foon rediffolv- ed; and that the fame alkali precipitates iron from vitriolic acid. He alfo fays, that regulus of cobalt cannot be precipitated from nitrous acid, nor arfenic trom aqua regia, by volatile alkali. Volatile alkali has no effet upon any metal not previouily diffolv- ed by acids, excepting copper, iron, and lead; the firft of which it diffolves perfeétly, a very fmall quantity of the fecond, and the third is very flowly changed by it into a kind of muci- lage. See Port fur la Diffolution des Corps. Vor. I, G ous I dl uo - JER | | ” ALK ALI ous matter. See SAL AMMONIAC, for the purification of vo- latile alkali, and for feveral of its effential properties. (5) The affinities of volatile alkali, according to Mr. Geof- froy’s Table, are, vitriolic acid, nitrous acid, and ma- rine acid. According to Mr. Gellert’s Table they are, phlogifton ; vitriolic, nitrous, and marine acids ; vinegar ; zinc; iron; copper; bifmuth; mercury; filver; and gold. Volatile alkali is employed in medicine as a powerful ftimulant and exciter, when applied fo that the perfon fhall inhale the vapors of it. Thus it is applied in faintings, nope, apoplexies, and in all lethargic difeafes, in which the nervous parts are benumbed and unbraced. In thefe cafes it is ufually applied in bottles, either in a concrete form called Englifb Salt, or in a fluid form, and reduced to a femi-faponaceous ftate by mixture with oil of amber, » when it is called Eau de Luce. See Sart (ENGLISH); and Eau pe Luce. * It may alfo be taken internally in thefe cafes, particu- larly in” apoplexies and lethargic difeafes, but in {mal} dofes, as from two or three grains to fix, and added to ftimulant mixtures. Taken in this manner, it fometimes is a powerful fudorific. M. Bernard de Juffieu has difcovered that this faline fubftance is a fpecific againft the bite of vipers; having cured as it were miraculoufly, by means of eau de luce, a ftudent of medicine, to whom this accident happened, while he was botanizing. “ALKALISATION. This name is applied to ope- rations by which alkaline properties are communicated to bodies ; or to thofe by which alkali is extrated from bo- dies which contain it, or in which it may be formed. For example, fr of wine is faid to be alkalifed when it has been digefted upon alkali, a part of which it diffolves, and (s) To the properties above-mentioned of volatile alkali, we may add, 1. That pure or cauftic volatile alkali, that is, when the volatile alkali is uncombined with gas or fixable air, fuch as the {pirit of fal ammoniac is when obtained by means of quicklime, is foluble in fpirit of wine; and that mild volatile alkali is not foluble in that fpirit : hence if a ftrong folution of mild volatile alkaline falt be added to fpirit of wine, the water of the {olution will combine with the fpirit, and the falt will be precipitated, forming what is called Offa Helmontii, 2. Mild volatile alkaline {ult requires four times its quantity of water to diflolve it: cauftic volatile alkali, as we have already obferved, is always combined with water. : thence A LLAY thence acquires alkaline properties. On the other hand when a neutral falt is decompofed in order to obtain its al- kaline bafis, this falt is faid to be alkalifed. Thus nitre deprived of its acid by detonation with inflammable mate Jorg, 8 charcoal, tartar, metals, fo that nothing remains Ey ofiaths is called Nitre alkalifed by Charcoal, or by Vegetable fubftances, when reduced to afhes, may alfo be faid to be alkalifed ; becaufc thefe afhes contain’ fixed alkali. See the detail of particular alkalifations, under the articles of the different ALK ALIS. ALKOHOL. This name has been given to any im- palpable powder. See PorpHYRISATION. Gonos tH) on given to highly rectified {pirit of wine. ALLAY. This word is employed in chemiftr - nify the union of different metallic matters. fry 158 As an infinity of different combinations may be made ac~ cording to the nature, the number, and the proportions of the metallic matters capable of being allayed, we fhall not here enter into the detail of the paricular allays, all which are not yet nearly known. Thofe which are ufed, as Bronze, Tombac, Brafs, White Copper, &c. may be found under their particular names; and what is known con- cerning other allays may be partly found under the names of the different metals and femi-metals and partly in this article. Metallic fubftances cannot unite dire@ly with earthy matters, not even with their own earths, when deprived of their inflammable principle, and confequently of their metallic properties. But in general it may be faid, that all metals may be allayed with each other, although more or lefs eafily, and although fome of them have not yet been made to unite. As metals are bodies naturally folid, the firft condition for their union is, that they be fufed. They then unite, like all bodies which reciprocally diffolve each other ; and from thefe combinations new compounds refult, which have the mixt propertics of the component fubftances. See Composition (CHEMICAL). In thefe metallic allays, as in almoft all other metallic combinations, phenomena appear which depart from the general rules of combinations. Thus it is obferved, that fome of the properties of metals forming an allay are al- tered, increaled, or diminithed by their union, The duc- G 2 tility, DREGE A LLAY tility, for inftance, of a metallic compofition is generally lefs than the duétility of the component metals alone and pure. The denfity or fpecific gravity of metals and {femie metals is alfo changed by allaying them with each other. Sometimes the fpecific gravity of the compound is interme- diate betwixt the fpecific gravity of the component metals, fometimes it is lefs, and frequently greater: this depends upon the nature of the metals. The fame obfervation may alfo be applied to the colors refulting from the allays of metals. Metallic allays are either natural or artificial. The firft are thofe made by nature, fuch as moft minerals, contain- ing feveral metals allayed with each other. Native gold is always more or lefs allayed with filver ; and native filver with gold. Artificial allays are thofe made exprefly for different ufes, or for the fake of examining their properties. Although the allays of different metallic matters are of great importance to the theory and to the practice of che- miftry, yet all the refearches which the fe deferves, and is capable of, have not been made. Mr. Gellert is one of thofe who have done moft in this way. In his Metal- lurgic Chemiftry there are a great number of experiments, which we fhall relate here fummarily. The experiments made for the allaying of femimetals with metals are his own, and were undertaken to determine the fpecific gra- vities of thefe allays. He relates the others before known, from chemical writings, and particularly from a Differta- tion of Mr. Kraaft exprefly on this fubject. We fhall refer the allays of mercury with other metals, called Amalgams, to the word AMALGAM. Gold may be eafily united with filver, and in all pro- portions. r. Gellert fays, that this allay is nearly of an intermediate gravity betwixt the gravities of the two metals, and but a very little augmented. This allay is of no ufe in the arts : on the contrary, as pure metals are always more du&ile than allays, in the arts where duétility is requifite, as in wire-drawing, and gold-beating, the pureft metals are chofen. (t) k Silver (t) The component metals of which metallic allays are formed may be either chemically combined, that is, mutually diffolved by each other ; or mechanically mixed, that is; diffufed through each other by the aétion of fire ; or they may be partly combines, an ALL AY Silver may be eafily allayed with copper, and in all pro- portions : copper alfo unites in the fame manner with gold. Gellert and partly diffufed, if the proportion of their quantities to each other be different from that which is neceffary for their combina tion. For moft, if not all, metals can be only combined with each other in certain proportions, as is very obfervable in thofe, the fufion of which requires very different degrees of heat. But thofe which may be kept fufed in nearly the fame degrees of heat, may be mixed together in almoft any proportion, and will be nearly uniformly diffufed throughout the metallic mafs when haftily cool- ed. As metallic allays have not been before confidered in this man- ner, no experiments have been made to determine the proporticns with which they can combine; nor can wefeafily eftablifh rules by which this kind of combination can be afcertained. ~Thofe, how- ever, which appear to be moft probable, for diftinguifhing this combination, are, 1. When an allay poflefles properties which nei- ther of its component metals had. 2. When the properties, as the {pecific gravity, color, hardnefs, &c. of the allay, are notin an in- termediate degree betwixt the fame properties of the component metals, according to the proportion of thefe metals to eachother. 3. When the component parts of an allay are not {eparable from each other by eliquation ; that is, by applying a heat capable of fufing one of them only ; nor by keeping the whole mafs in fufion, with a heat not more intenfe than is neceffary for that purpofe, but in- fufficient to occafion an ebullition, and by cooling the melted mafs very flowly. When therefore, according to thefe rules, a metallic allay has no properties but thofe which its component metals had ; when its denfity, color, hardnefs, elafticity, fufibi- lity, and other properties, are precifely in an intermediate degree ~ betwixt thofe of its component metals ; and laftly, when 1ts com= ponent metals may be feparated from each other by eliquation, or by giving them fuch a fluidity and reft as that they may fepa- rate according to their refpective denfities ; we may then, with probability, pronounce that this ailay is compofed of parts not chemically combined : and when to an allay, which by thefe rules is compofed of metals chemically combined, a quantity of one of the fame kinds of metal of which the allay was compoled, is added, and, upon examination, the new allay is found to poflefs no properties but fuch as are intermediate betwixt the firft allay and the added metal, and to be feparable by eliquation, or by fufion according to their different denfities, we may then con- fider this new allay as a mafs confifting of metals partly combined, and partly diffufed. That the allay mentioned in that part of the text to which this note refers, namely, that of gold with filver, does not confit of parts chemically combined, or elfe, that but a very fmall proportion of cither of thefe metal e 3 combined I EEE ———— ALLAY Gellert obferves, that the allay of filver and copper is of 2 greater than the intermediate gravity ; but that the allay of gold and copper is of a gravity lefs than intermediate. Copper renders gold and filver harder and more fonorous, without much diminution of their dultility. It has even the remarkable property of rendering thefe two metals lefs fufceptible of ng their duétility by the vapor of charcoal, which they are very liable to do; copper alfo heightens the color of gold. Thefe properties of copper relatively to gold and filver render its allay with thefe metals of great ufe to gold and filver finiths ; becaufe it makes thefe metals firmer, and fitter for working and chafing; and alfo for making money, for the fame reafons ; and for the payment of the duties of Government, and for compenfation of the expences of coining. ‘The quantity of copper allayed with gold and filver for thefe different ufes varies according to the different countries, but in each country it is fixed, and always the fame. | Iron allays well with filver, and fill better with gold. Gellert obferves, that the gravity of an allay of gold and iron is lefs than the intermediate. The affinity of thefe two metals is very great; for gold facilitates its fufion, which indicates a ftrong difpofition to unite, Gellert obferves upon this occafion, that therefore gold is fitter than copper for foldering fine works of iron and feel. (2) Iron unites difficultly combined with the other, appears probable from the following reafons ; 1. The denfity of the allay is very nearly intermediate between the denfities of the component parts. 2. The filver and gold are not uniformly and equally diftributed through the whole mafs. This ines uality is proved by an experiment of Mr. Hellot, He meited a mafs of 20 pounds, containing g; parts of filver and one part of gold, and poured it into three feparate mafles, each of which was found by effay to contain a different proportion of gold from the two others. 3. Gold and filver kept in gentle fufion are feparakle from each other, merely by means of their different denfities. Mr. [Homberg kept equal parts of gold and filver in gentle fufion a quarter of an hour, and found, upon breaking the crucible, two mafies, of which the upper was pure filver, and the lower the whole gold allayed with ith part of filver. He repeated the experiment with nearly the fame event ; and twice he obtained the two metals perfeltly feparated from each other. See a note to the grticle AFFINITY. (u) A very fmall quantity of iron renders gold hard, brittle, and pale, So hard are fome mixtures of iron and gold, that they RAE - are AL LAY i with copper, and in finall proportion, It renders am The portion of iron which does not unite with copper forms a feparate regulus, which, however, ftrongly adheres to the furface of the regulus of copper. The degrees of affinity of iron with other metals, accord- ing to Gellert’ Table, but reverfing the order in which he has placed them (that is to fay, beglnoms by thofe with which it has the ftrongeft affinity, which feems to be the moft natural order), are, gold, filver, and copper. Tin, according to the fame author, unites with all metals, and renders them brittle ; iron and lead it alters leaft in this refpe. (w) But gold and filver are fo affected 5 on, that its vapor alone is capable of deftroying the ductility o a large quantity of thefe metals, as is well known to arti- oe he allays of tin with gold and filver are therefore of no ufe; on the contrary, they are carefully avoided ; but wih copper tin forms an ufefu compound, known by the name A we ) 1 of § Bronze. The fpecific gravity of allays of filver and of ret with tin is greater, and that of gold with tin 1s lefs than the intermediate. The affinities of tin with other metals, according to Gellert’s Table (only roverfing his 1 order, which we fhall always do), are iron, copper, iilver, S ’ . . . Bo a unites with all metals, excepting iron, with which no method has been found to unite it. Gellert obferves, that this property of iron with regard to lead renders it fit 0 feparate this latter metal from others, proyided that oe metal from which it is to be feparated has not a greater dif- pofition to unite with lead, than the iron has to unite with it. ‘This is certain, that lead may ferve as an intermedium by which iron may be feparated from other metals : for 32 ffance, from filver. For if a {ufficient quantity of lead be melted with filver allayed with iron, it will cafily feize upon the filver, and feparate the iron from it, which will then {wim upon the furface of the two melted metals, The allays of gold and of filver with lead have 2 greater fpecific gravity, and the allays of copper and of tin wit jead have a lefs {pecific gravity, than the intermediate, are {aid to have been formed into razors. Three or four parts of iron and one part of gold compofe an allay nearly as white as filver. 4 : (w) Equal parts of tin and iron form a white but brittle fs. my G 4 The ALLAY The allay of lead with other metals is ufed for the effays of ures, for refining, and for liquation. See LiQuaTion. Lead and tin are allayed together to form a folder for pipes and other works of lead. . ~The affinities of lead with other metals, according to Mr. Gellert’s Table, are, filver, gold, tin, copper. | Zinc may be allayed with all metallic matters, excepting bifmuth, with which it cannot unite, according to Mr. Gellert. . This femimetal, when united with metallic fuh- ftances, gives fufibility to. thofe which are lefs fufible than itfelf. ~The denfity of allays of gold, of filver, of copper, and of lead with zinc is greater; and that of allays of the , fame femimetal with tin, iron, and regulus of antimony, is lefs than intermediate. The allays of zinc with moft metallic matters are not ufed in the arts, but that with copper is very much. This allay forms Brafs, Tombac, Prince's Metal, Pinchbeck, &c. The affinities of zinc with other metallic matters are, - according to Gellert’s Table, copper, iron, filver, gold, tin, lead partly; that is, it does not unite with lead in all pro- portions. Bifmuth unites with all metals, and with moft femimetals, It has fo great action upon other metallic fubftances, that it fenfibly facilitates their fufion. (x) Bifmuth renders all the metals with which it is united brittle. It does not unite with zinc; nor, according to Mr. Gellert, with arfenic, (x) Bifmuth greatly increafes the fufibility of fome metals, as appears from the following “i'able of Dr. Lewis, in which the fe g7ces of heat are marked in numbers according to Fahrenheit’s cale. Coo. Mercury boils. 540. Lead melts. 460. Bifmuth melts. 410. Tin melts. 390. Tin 8 parts, bifmuth 1 part, melt, 330. Tin 2 parts, bi math 1 part, melt. Tin 3 parts, lead 2 parts, melt. 280. Tin and Bifmuth, equal parts, melt. 22. Water boils. Mr. D’Arcet has, in the Fournal de Medicine, (June 1775) publithed an account of fome experiments made to. difcover the proportions of lead, tin, and bifmuth, which fhould produce the moft f fible allay. He found that a mafs confifting of eight parts of bifmuth, five parts of lead, and three parts of tin, melted in boiling water, and even in balneo marie, Ps When A LLAY When melted along with zinc, it remains at the bottom of the crucible, as being the heavier of the two; and when ‘they are cooled, they are found forming two diftiné&t reguli -adliering ftrongly to each other. Gold, filver, lead, and regulus of antimony form with bifmuth allays of greater, and iron forms an allay of lefs, than intermediate denfity, and copper forms with it an allay of intermediate denfity. The allays of bifmuth are not in ufe, excepting fome par- ticular metallic compofitions for mirrors. The affinities of bifmuth with other metals are, according to Mr. Gellert’s Table, in the following order: iron, cop- per, tin, lead, filver, gold. « Cobalt” *, fays Mr. Gellert, ¢ may be allayed with « all metals and femimetals; but it acts little upon lead « and filver. When equal parts of lead and cobalt are ¢¢ melted together, thefe two fubftances are found only «¢ adhering to each other, the lead being, in confequence of «¢ its greater fpecific gravity, at the bottom of the crucible, -¢¢ and the cobalt above it; fo that it feems probable that <¢ they are not at all combined. But if the fame cobalt be «¢ melted, after it has been thus treated, with iron, which ¢ feems to be the moft readily united with it of all the ¢¢ metals, a fmall regulus of lead is found at the bottom of ¢¢ the crucible, becaufe iron and lead do not unite. At « firft, we might be apt to believe that filver and cobalt do ¢¢ not unite together. In fact, if two parts of cobalt and ¢¢ one part of filver be melted together, the filver is found at ¢¢ bottom and the cobalt above, only adhering to each ather : ¢¢ But the filver is become more brittle, and of a greyifh ¢¢ color; and the cobalt is become whiter than before. If ¢¢ this filver be cupelled, the part of the cobalt united with ¢¢ it will attach itfelf to the cupell in form of a circle, and ¢¢ the filver will be found to have loft an eighth part of its ¢¢ weight, which will be found upon eflaying the cobalt, ¢¢ and examining how much filver it contains.” Metallur- gic Chemiftry, Tom. 1. Thefe experiments of Mr. Gellert’s prove, that regulus of cobalt cannot be united to lead and to filver in all pro- portions, but only in {mall quantities. The fame may be faid of bifmuth, with which, fays Mr. Gellert, cobalt is * Note. By Ccbalt Mr. Gellert certainly means what we call Regulus of Cobalt; for Cobalt properly called is a mineral com- pofed of other fubftances befides the regulus of cobalt, as {ulphur, arfenic, bifmuth, filver, and unmetallic earths, See CoBaLT. very ALL AY .afily united : for Mr. Beaumé, who has made many ex i on the regulus of cobalt, has obferved, that when this regulus is melted with bifmuth, thefe two metals are found feparate, the bifmuth being at the bottom of the cru- cible and the cobalt above it. The allays of the regulus of cobalt are but little known, and not ufed in the arts, In Mr. Gellert’s Table, the affinities of regulus of cobalt with metallic matters are in the following order: copper, Aron, tin, zinc, regelug of antimony, bifmuth and lead, ] and arfenic, partly. Rm of iy be allayed with almoft all metallic fubftances. Mr. Gellert fays, that the denfity of allays of this regulus with iron, tin, or zinc, 1s lefs than intermediate, and that the denfity of allays of this regulus with filver, copper, lead, and bifmuth, is greater than in- termediate. He obferves alfo, that the magnetic property of iron is much more diminithed by an allay of that metal with regulus of antimony than with any other metallic fub- A ys of regulus of antimony are little ufed in the Bees, it is ufed in fome compofitions for fpeculums. An allay ° this femimetal with iron, tin, and copper, 1s made pe the preparation of a medicine cals Lilly of Paracelfus, or Tine- 5, See LiLLY of PARACELSUS. Ferien of the on of antimony with metallic fubftances are placed by Mr. Gellert in the following ober) zinc, copper, tin, lead, filver, gold, Bifmuth is fop Jace in the Table as to denote its incapacity of uniting with the us of antimony. rE oe, or its ers unites with moft metallic matters, Mr. Gellert fays, that it whitens iron ; but the allay ref u “ ing from thence is very brittle. Copper is alfo ren ae very white by mixture with arfenic. This is the white ws ac which refembles filyer. Mr. Gellert affirms, that this a lay, notwithftanding it contains arfenic, is fufficiently ductile and malleable, which is very remarkable. But if it Somali too much arfenic, it is brittle, and blackens in its fur ace: Arfenic united with tin is partly reduced toa powder ¢ afhes, in which much of the arfenic remains, I ® re Ae the tin is very brilliant, foliated, and externally re pes zinc, without being poffefled of any of its properties. 11} alfo becomes much harder and more fonorous by this nia, Lead united with arfenic fmokes and fwells more quickly with a2 moderate fire than it does alone ; a part of it oS lik ALLAY pated in form of a thick fmoke ; another part is changed into a glafs of a reddith yellow color ; and the remaining lead is brittle, and dark-colored. Arfenic unites with filver, and renders it brittle. It does the fame to gold, and alfo de- prives it of its color, rendering it pale. It unites very difficultly with cobalt, with which it forms a black, fhining matter. Laftly, Mr. Gellert (from whom all this is extracted) fays, that bifmuth cannot be united with arfenic, In this author’s Table of Affinities, the metallic fubftances capable of uniting with arfenic are placed in the following order, which is the fame as that for the regulus of antimony : zinc, iron, copper, tin, lead, filver, gold, regulus of anti- mony. The allays of arfenic ufed in the arts are white tombacs, and fome compofitions for {peculums. It is neceflary to remark on the fubjeé of arfenical allays, that this fingular fubftance has the property of uniting with metals even when itis deprived of phlogifton, and in an unme- tallic ftate. This proceeds from its faline chara&er, and from its property of taking phlogifton from the imperfe& metals and from the femimetals ; confequently there ought to be a difference betwixt the allays made with white cryftalline arfenic, and thofe made with the regulus of arfenic. See ARSENIC, and REGULUS of ARsENIC, (y) It is proper to obferve, that chemifts who treat of metallic allays differ much from each other in the defcriptions they give of the refults of their experiments, as may be feen in the particular articles of each metallic matter, which ought to be confulted on this fubject, But thefe differences are not furprifing, when we confider the difficulty of the matter, and the great obftacles which prevent perfe@& exaénefs in thefe experi- ments. All who have operated much in chemiftry will eafily perceive, that, without reckoning the difference of proportions of the metals employed in the allays, which mutt greatly affeét the refults, others much more confiderable would occur, depending on the purity of metals, on the (ry ) The author of the Di&ionary has omitted, in the enume- ration of allays, thofe of Platina, and of the femimetal difco- vered by Mr. Cronftedt, called Nickel. For thofe of Platina, fee the article PLaTina. Nickel may be allayed with all metallic fubftances excepting filyer, mercury, and zinc. By means of nickel the two femimetals bifmuth and regulus of cobalt may be united. It whitens copper and gold, and it renders the malle- able metals hard and brittle, greater A LLAY greater or lefs quantity of phlogifton with which many of them are capable of being united, on the very variable de~ ftructibility and volatility of many metallic matters; and laftly, on the juft degrees of heat, which are of confiderable confequence, and which it is almoft impoflible to determine precifely. ® From thefe obfervations we ought to conclude, that, in order to make a fett of accurate experiments on metallic allays, and which may be depended upon, it is, in the firft lace, necefiary that 211 the metallic matters to be employed Pe exceedingly pure, which is a matter of great difficulty: in the fecond place, it is proper to make all the fufions in veflels perfeétly clofe, to prevent the alteration, the burn- ing, and the deftsuction of thofe metals which are liable to thofe events: laftly, to determine carefully the precife degree of heat requifite for the beft combination of metallic matters with each other. But it does not appear that any perfon has hitherto done this great and important work ; it is to be wifhed that it were undertaken. How many fine experiments might be made upon all thefe allays, todifcover their properties ! What has been already done in this matter is, however, {ufficient to eftablifh fome general truths, Several have been explained in the beginning of this article. Another evidently refults from the experiments of M. Kraaft and M. Gellert : it is this, That as in the union of all other bodies, fo in that of metallic {ubftances, fome are more eafily foluble, and in all proportions; others more or lefs difficultly, and only in certain proportions; and laftly, others appear inca~ pable of uniting in any manner. On thefe two latter cafes it is very important to obferve, that this property which certain metallic matters have of diffolving others in certain proportions only, is very capable of .impofing on the operator, and of perfuading him that one metal cannot be united with another, becaufe he fees after the fufion two diftiné reguli, while in fat there is a quantity, though frequently a very {mall one, of one of the metals united with the other. “This is fimilar to what happens in the combination of fpirit of wine with oils, and of water with ether. Chemiits believed long that ether was infoluble in water, becaufe when thefe two liquors were put in the fame veflel they conftantly feparated, the ether, being greatly the lighter of the two, rifing upwards, and floating on the furface of the water, But the Count de Lauragais, having examined the matter more siteniivelsy ar E Clg 28 a sh SS AR BR ALUM and in a truly chemical manner, demonftrated, in a memoir read at the Academy of Sciences, of which he is a member; that ether is really foluble in water, but only in a certain proportion. Sez ETHER. This being eftablithed, perhaps we fhould find, if we were to examine all the mixtures of metallic fubftances, that thofe which have hitherto been confidered as incapable of union are, neverthelefs, very capable of it, but only in certain proportions ; and if fome are found which cannot by ordinary fufion be united, we might ftill try to break their aggregation more compleatly, and then to apply them to each other, as the Count de Lau- ragais has done with fulphur and fpirit of wine. See Com- pINATION ; CoMPosITION (CHEMICAL). ALUDELS. Chemifts give this name to certain pots or capitals which are open at both the upper and lower ends, and may be inferted and applied above each other, fo that the whole fhall form a pipe or tube more or lefs long accord- ing to the number of aludels compofing it. The aludel which terminates this tube above, ought to be clofed in its upper part, or to have but a very {mall opening. The tube compofed of thefe aludels is nothing but a kind of capital or head, which may be enlarged or lengthened at pleafure, and adapted to a cucurbit. This apparatus is intended to collect and retain dry and volatile matters, which may be reduced into flowers by fublimation. It may be employed for the preparation of flowers of fulphur, of arfenic, of anti- mony, of benjamin, &c. See SUBLIMATION. See alfo Pirate L. ALUM. Alum is a cryftallizable falt compofed of vitriolic acid united with an argillaceous earth. This falt has an auftere, fweetith, and ftrongly aftringent t.fte. This ftrong tafte proceeds from the ftrength of union betwixt the acid and its bafe being lefs than in other vitriolic falts with earthy bafes ; fuch, for example, as felenites, which has no fenfible tafte. Mr. Beaumé has even obferved, that the acid of alum is not exaétly faturated; for it is certain that it reddens turnfol and blue paper. This falt diffolves fufficiently well in cold, but in much larger quantity in boiling water. (z) It is confequently fufceptible of cryftallization by the evaporation and cooling of the water in which it is diffolved. The figure of the (z) Neuman fays, that alum requires ten times, and other i fay it requires fourteen times, its weight of water to dif- olve it. cryftals ————— ee - ew ee mas a SE ! AL UM ; eryftals of this falt varies, like that of other falts, according to the circumftances concurring during the cryftallization: Wher its folution, evaporated to the cryftallizing point, is made to cool flowly, the greateft part of its cryftals are found to be triangular pyramids, whofe four angles feem “cut off. Alum retains half its weight of water in cryftalli= zing, “This great quantity of water in the cryftals of alum, to- gether with its property of greater folubility in hot than in cold water, is the caufe that when put in an earthen or iron veflel, on a good fire, it enters into a liquefaétion, which gradually diminifhes as the water evaporates. When it is entirely evaporated, which is not foon, the alum which had fwelled much during this operation, remains dry and friable; it is then called Calcined Alum. After this evaporation, it may be again diffolved in water, and cryftallized as before. Although the acid of alum appears, as its tafte and folu- bility indicate, to be lefs intimately combined with its bafts than the acid of felenites is, yet but a very fmall quantity of it can be difengaged by the ftrongeft fire. Mr. Geoffroy put fome calcined alum into an earthen retort, and expofed it to a moft violent fire continued during fix days and fix nights ; and from five pounds of alum thus treated he ob- tained only three ounces of vitriolic acid, although it is certain that this falt contains a much greater proportion of acid, as we fhall foon fee. The acid thus obtained by diftillation from alum is called Spirit of, Alum; and does not differ from pure vitriolic acid. : Alum may be eafily decompofed by feveral intermediate {fubftances. Firft, as the acid of alum is certainly the vitriolic, all fubftances which have a greater affinity than earths to vitrio- lic acid, are capable of uniting with it, and of feparating from it its earthy bafis. | Alum, therefore, treated properly with any matter con- taining phlogifton, may be decompofed; its acid uniting with it, and forming artificial fulphur. Sec SULPHUR. It is by means of this artificial {ulphur, which is formed during the calcination of alum with any vegetable or animal matter, that the pyrophorus of Homberg is made, which has the property of burning merely by contact of air. See Py- ROPHORUS. In the fecond place, all faline alkalis are capable of decompofing alum. This decompofition may be made in the humid way. ‘Thus if any alkali be added to a {olution of ALUM of alum, the liquor immediately becomes turbid and white, and a fediment is formed, which is the earth of alum fepa- rated from its acid by the intervention of alkaline falt. On the other fide, the new falt formed by the union of the acid of alum with the alkali, may be cryttallized by evaporating the liquor. If fixed vegetable alkali was employed for this precipitation, vitriolated tartar is formed : if mineral alkali was employed, Glauber’s falt is formed. “Lhis decompofi- tion of alum is a very convenient method of preparing thefe two falts. Laftly, if volatile alkali be employed for this precipitation of the earth of alum, vitriolic ammoniacal falt will be formed. Calcareous earths, and even fome metallic fubftances, are capable of decompofing alum. The former are fo, becaufe their affinity is greater than that of the argillaceous earth of alum with the vitriolic acid; and the latter, for inftance iron and zinc, are fo, becaufe of the flight adhefion of their phlogifton. it appears that Mr. Geoffroy was the firft who difcovered that iron could decompofe alum ; and this he did by boiling alum in an iron pot. This experiment of Mr. Geoffroy is found in the Memoirs of the Academy of Sciences. What has been faid concerning thefe different decompo- fitions of alum proves inconteftably, that the acid of this falt is the pure vitriolic; and this truth has been known a con- fiderable time; but till lately, the nature of the earthy bafts of alum was not precifely and diftinétly underftood. For a long time it was confidered by chemilts as a calcareous earth : but accurate experiments have fince thewn, that calcareous earths, united with vitriolic acid, formed {elenites and not alum, which are entirely different; and that the earth of alum could not decompofe fal ammoniac, nor be converted into quicklime, nor had any of the diftinguifhing properties of calcareous earth. Thefe experiments have been made by Pott, Margraaf, and Baron. This lait chemift, ftruck with the differences betwixt earth of alum and calcareous earth, and with the refemblance betwixt alum and moit vitriolic falts with metallic bafes, has given a Memoir to the Academy of Sciences, in which he conjectures that this earth of alum is of metallic nature. On the other fide, there were experiments which proved that the earth of alum was contained in clays. Mr. Geof- froy and Mr. Hellot had faid, that, by digefting clays with vitriolic acid, they had obtained falts of the nature of alum. Hellot, having employed a clay as an intermediate {ubftance 3 in ALUM in the diftilation of the ether of Frobenius, perceived that the vitriolic acid of this mixture had deprived the clay of all its argillaceous properties, by taking from it an earth, which being again feparated from this acid by an alkali; had all the properties of pure clay. See Memoirs of the Academy for the year 1739. Mr. Pott, who quotes in his Lithogeognofia this experiment of Mr. Hellot, having fatisfied himfelf with regard to the properties of the alum obtained by digefting vitriolic acid upoh clay, concluded that the earth of alum is of an argillaceous nature. Sec Potts Lithogeognofia. Mr. Gellert in his Metallurgic Chemiftry, and efpecially Mr. Margraaf, in three SE entions upon alum, have men- tioned the fame experiments, and have drawn from them the fame conclufions. Laftly, Mr. Macquer, in a Memoir read at the Academy in 1762, concerning clays and their fufibi- Lity when joined to calcareous earth, after having quoted the above citations, which are extraéted from that memoir, places the affair beyond doubt, by adding his own experi- ments and obfervations to thofe already made. AMMONIAC AL Sal ammoniac may be purified from this ext y the means commonly employed for the purification of falts, that is, by diffolving in water, filtrating, cryftallizing; and by fubliming a fecond time, if this thould be thought necef- fary : a fal ammoniac is then obtained perfectly white and pure. Sal ammoniac may be made by combining marine acid to the point of faturation with vol from the diftillation of animal of by filtrating, cryftallizing; and fubliming the faline matters thus combined. But this fa] ammoniac would coft more than the price it is generally fold for; Although the volatile alkali ufed for this procefs, folid or liquid, be very impure and impregnated with much eémpyreumatic oil, from which vegetable fubftances, and tained by decom- fing fal ammoniac is better difengaged from all fuperabundant oily matter than what is obtained by any other method, But we muft ebferve, that the volatile alkali obtained from {al ammoniac always carries off with jt fome of the fubftance employed for the decompofition. This circumftance muft produce different effes in chemical experiments, to which attention ought to be given. (g)- ‘ AMMONIACAL SALT (VITRIOLIC). This is a netural falt compofed of vitriolic acid faturated by vola~ tile alkali. : This falt may be made by feveral different methods, 5 I. Sal ammoniic re. diffolve in that liquid: repeated fublimarions, the fubliming veflel ; blimed together with duum of each preceding the whole matter became that it remains half fluid at the bottom of and when fal ammoniac was repeatedly fu mercury corrofive fublimate, and the rej; operation mixed with the fublimed falt, quite fixed in the fire, and would no longer rife from the bottom of the glafs. Neuman. 3: The degree of heat neceffary to volati- lize fal ammoniac is a little below that of ignition, nearly the fame with which lead is melted. 4. Pott fays; that a {mall quan tity of fal ammoniac may be produced by diftilling fea.falt with charcoal or with alum, or by dittilling marine acid with Armenian ole. ¢. The fame author affirms, that the inflammability of Tulphur is deftroyed by fubliming it with twice its quantity of fal ammoniac, . 2 1. By raneous matter - atile alkali, obtained - A nae | i H i i i $ | i ] % i i | AMMONIAC ; 3 By eombining vitriolic acid with difengaged volatile alkali. 2. By decompofing fal ammoniac by vitriolic acid in Glauber’s manner. Yr this latter method be ufed, a marine acid is obtained by diftillation, ftrong in pro ortion to the concentration of the vitriolic acid ot ; and in the retort the vitriolic ammoniacal falt remains, which Glauber called his fecret fal ammoniac. ; 3. Bydecompofing all vitriolic falts with earthy or metallic bales, by means of volatile alkali. Se ALKALI (VOLATILE). This falt has the properties of fal ammoniac, with the differences depending on their different acids. It is femi- volatile ; it may be entirely fublimed ; it cannot be decom- pofed in clofe veflels without fome intermediate fubftance ; it has a fharp tafte ; it eafily diffolves in water ; and is fuf- ceptible of cryftallization. This ammoniacal falt is net ufed in arts or in medicine. Glauber attributes many wonderful properties to it, which it certainly does not, fo eminently at leaft as he pretends, poffefs. AMMONIAC SALT (NITROUS). This falt is compofed of nitrous acid faturated with volatile alkali. It :s found in earths, or plafters where nitrous acid is gene- rated, when thefe earths have imbibed a fufficient quantity of putrid animal or vegetable fubftances to furnifh volatile alkali to the nitrous acid, which is there generated. Nitrous ammoniacal falt may be made, as the vitriolic, by three methods. tr. By combining to the point of faturation nitrous acid with volatile alkali. 2. By decompofing fal ammoniac by means of nitrous acid. . By decompofing nitrous falts with eagles metallic eles, by means of volatile alkali. See ALk ALI ( VOLATILE]. _ Nitrous ammoniaca} falt has a very pungent tafte; is {oluble in water ; capable of forming beautiful needle-like cryftals, like thofe of ordinary nitre. This fale has the fingular property of detonating alone, when expafed fo a certain degree of heat, and without the neceflity of addition, as in ordinary nitre, of inflammable matter. It feems even to inflame with lefs heat than nitre mixed with inflammable matter does. This property proceeds from the phlogifton or inflam- mable matter which enters as a principle into the compofi- tion of the volatile alkaline bafis of this falt. This pro- perty alfo furnifhes a decifive proof of the exiftence of this inflammable matter in volatile alkali. TE is AMIANTHUS “This inflammability of nitrous ammoniacal falt renders it incapable of fublimation, like the other ammoniacal falts, as. an explofion would certainly happen in the operation. Che- ; mifts do not feem to have examined particularly the pro- perties of this falt; neither is it ufed in arts or in medicine. If this curious falt were to be more particularly examined, the operator would need the greateft circumf{pection to avoid explofions. : AMMONIACAL SALT (VEGETABLE). This name is given to all neutral falts formed by combina- tions of valatile alkali with vegetable acids. But thefe falts are hitherto little known, although they deferve to be exa- mined. The faline combination formed by volatile alkali " and vinegar is called Spirit of Mindererds. AMMONIACAL SALT (ANIMAL). As the fat of animals contains much acid (See FAT), an ammoniacal falt might be formed by combining this acid with volatile alkali, which might be properly called animal ammoniacal falt, But this combination has not yet been made, or ex= amined, : Laftly, the phofphoric falt, or native falt of urine, be- longs to the clafs of amimoniacal falts; and as its acid appears to be peculiatly animal, it wauld alfo be in this {enfe a true apimal ammoniacal falt. See Sart (FusisLE) of URINE. AMMONIAC (FIXED). (7) AMMONIAC uM, (s} AMETHYST. (1) AMIANTHUS. (x) ANALYSIS rr) Fixep Ammon1ac is a name given to the refiduum formed by decompofing fal ammoniac with a calcareous earth. It is a falt compofed of that earth and marine acid. See Sart (Marine) avith Basis of Carcareous EarTs. (s) Gum AMMoONIAC is a gum refin, from an ounce of which fix drams may be diffolved by fpirit of wine, or fix drams two {cruples and a half may be diffolved by water. Neuman. (1) AMETHYST. This is a violet-colored, frequently yellowith or reddifh, pellucid gem, the feventh in degree of hardnefs from diamonds, fufible by fire, which alfo deftroys its color. It is found amongft quartz, and is probably only a colored quartz cryftal. This fone may be imitated by adding to a fritt of cryftal- glafs eight parts of magnefia and one part of zaffre. (v) AmianThus is the lighteft and fofteft of all fones. It sonfifts of fibres parallel or elev, fo fiexible, that cloth has 3 been i ——— —— " EL ANALYSIS ANALYSIS. Chemifts underftand by the word ana- lyfis, the decompofition of a body, or the feparation of the principles and conftituent parts of a compound fubftance. Chemiftry furnifhes feveral means for the decom ofition of bodies. Thefe means are all founded on the differences of the properties belonging to the different principles of which the body to be analyfed is compofed. Thus, for example, if a body be compofed of feveral principles, fome of which have a great, and others a moderate degree of vola- tility ; and, laftly, others are fixed, its moft volatile parts may be firft feparated, by a graduated heat, in diftillin veflels, and then the parts which are next in volatility will ts over in diftillation ; and laftly, thofe parts which are xed, and capable of refifting the ation of fire, will remain at the bottom of the veflel. As this analvfis cannot be made but by means of fire, it is called the ai by fire. It 1s proper to obferve, that this method of analyfing does not {ucceed equally well upon all bodies, and that it is very imperfe&t upon fome bodies, which being compofed of prin- ciples of very different degrees of volatility, might feem well adapted to it, This particularly happens when the principles of fubftances analyfed by this method have a great adhefion to each other; becaufe in this cafe a volatile princi- ple drags along with it a portion of the fixed principle, which would never have been raifed b the degree of heat employ- ed without this adhefion, oh as it were, participation of the volatility of the former with the latter. F requently, therefore, the principles obtained by this method of analyiis are in part {till united with each other, and are far from the proper degree of purity. In this cafe it is neceflary to have recourfe to new diftillations, re¢tifications,. and “purifica- tions, to obtain them fufficiently pure and feparated from each other. This inconvenience particularly attends the analyfes by fire of moft animal and vegetable fubftances, in which analyfes very volatile acids and alkalis are often procured, ftill united with much fuperfluous heavy oil. The beft method of avoiding this inconvenience, or at leaft of diminifhing it as much as poflible, is to manage very care- been formed of them. By a ftrong heat it is whitened, hardened fo as to be capable of ftriking fire with fteel, and rendered brittle, Fe has generally been confidered as unfufible by fire ; but Mr’ D’Arcet, in a Memoir of the French Academy for the year 1766" affirms, that by a violent and pkg eontiuded fire it is fufible’ znd that it forms a black glafs. s ftone is infoluble by acids’ fully ANALY S1S the fire; for it is evident that a too ftrong fire would al ily confound all the principles of the ick. to be d. ; gh no lefs important remark concerning the ana- lyfis by fire, is, that by this method the proximate principles of. very compound bodies, fuch as moft vegetables; cannot be obtained ; becaufe thefe proximate principles being them- felves very compound, and of a delicate mixture, cannot, for the moft part, fupport the action of fire without a total or partial decompofition ; or, at leaft, without receiving fuch confiderable alterations that they can no longer be known. This inconvenience chiefly attends thofe proximate prin- ciples which are not poflefled of great volatility, as we may fee from "the EE of mild and fat oils, of gummy, refinous, faponaeeous, and extractive parts of vegetables. Thele principles cannot ever be procured by diftilation fuch as they were in the plant. Thefe inconveniences have induced chemifts, particularly the modern, to fearch for other Medhjels of decompofing eparating their principles. i Bs bs Pred oe rictiod which wonderfully fupplies in many cafes the defects of the analyfis by fire. | This fecond method of decompofing bodies 1s founded on the different degrees of folubility in moft menftruums, which the different principles pofle(s. Thus when a body is com- ounded of feveral fubftances ; one of which, for inftance, is foluble only by fpirit of wine, a fecond is foluble only by water, and a third is foluble only by ether ; thefe fubftances may be very eafily feparated from each other, by fubmitting fucceffively the compound body to the action of thefe men- ftruums, each of which diffolves that particular fubftance to which it has an affinity, and from which it may be after- wards eafily feparated. ~ This method of analyfis is excellent fo feparate without any fenfible alteration the greateft part of the proximate principles of vegetables, and to obtain them as they exit in the plants. If, for inftance, a vegetable matter contain gum, refin, and an oil or oil concretion not foluble in fpirit of wine; we may firit deprive it by water of its mucilaginous and gummy parts, which may afterwards be obtained in their natural ftate merely by eva- poration of the water; then, by applying to this-vegetable matter fpirit of wine; we may extract its refinous parts; and laftly, we may, by treating it with ether, feparate its oily part, which could net be diffolved by the water Spin of wine. It is dhl to obtain the hava ANAL YSYS diffolved by the ether and fpirit of wine, pure and free from their menitruums; either by evaporation, or by addition of much water, which feparates the oily and refinous parts, See SPIRIT of WINE, and ETHER. As this method of feparating the principles of bodies is folely founded on the action of menftruums, this kind of analyfis has been called ANALYSIS by MENSTRUUMS. What has been faid on this fubject is fufficient to thew its great utility. We may add, that .in fome cafes this is the only analyfis which can be applied, and ‘by which a perfe& and compleat feparation can be effected. If, for example, the body to be analyfed confifts of two fubftances which equally refift the ation of fire, as gold and filver, it is evi- dent that thefe two fubftances cannot be feparated from each other but by means of a menftruum which can only diflolve one of them. Thus, by expofing a mafs compofed of gold and filver to aqua regia, which diflolves the gold only, or to nitrous acid, which diflolves only the filver, the feparation of thefe two metals may be effected. The opera- tion called Parting ought then to be confidered as the true analyfis by menftruums. 8ee PARTING. We may fay the fame of all decompofitions and precipita- tions which are made in numberlefs chemical operations by intermediate fubftances, either by the humid or by the dry method, in different fufions. In all thefe cafes, the inter- mediate fubftance employed effects the precipitation or fepa- ration of the body intended to be feparated, by reall &it- folving another body to which the former was united. Thus the analyfis by menftruums is at leaft of as extenfive utility as the analyfis by fire, fince it takes place in almoft all the operations of chemiftry. It is true, that in many cafes the analyfis by menftruums, as well as that by fire, is incomplete. This inconvenience happens when there is in the compound body to be analyfed fome intermediate fubftance, by means of which the men- ftruum is rendered capable of ating upon fome of the principles, which it ought not to do, in order to have a complete and perfect feparation, But thefe inconveniences may be prevented or remedied. ¥ requently it is'neceflary, in order to make a perfect ana- lyfis of bodies, to unite thefe two methods by fire and by menftruums : the one may be made to affift the other ; and from thefe combined means a decompofition refults much more perfect, and more accurate, than could have been ob- tained by either of them feparately. If, for inftance, we intended ANNOT TO intended to feparate from fpirit of wine the fi uperabundant -quantities of oil and water which are generally united with it, we ought, inftead of diftilling it alone, to mix with it fome fixed alkali, or very dry earthy matter, and then to proceed to the diftillation : helo alkaline or earthy fubftances acting upon the oil and water will retain and fix them ; by which means the fpirit of wine is allowed to rife much purer in diftillation. We fhall fay nothing more here upon analyfis in general. This fubject is fo extenfive, that to make particular appli- cations of it, we fhould be obliged to confider all the objets in chemiftry. Thofe who know the ufe of general prin- ciples will eafily apply thefe to particular operations; and longer details would be fatiguing and ufelefs to others. It is neverthelefs proper to mention the general articles which are related to this. See DEcomPosITION, DistiLLaTION, SusLiMATION, PRECIPITATION, EXTRACTION, SOLU- TION, ANGELICA. (w) ANIMAL. (x) ANIME. ANISE. " (z) ANNOTTO. (a) ANTIMONY. (w) Ancerica. The rootof this plant contains an effential cil, and a refinous matter. Newman. (x) Anximar KincpoM. See Kincpom. . (3) Anime, according to Neuman, is a refin totally foluble in fpirit of wine. It is called improperly gum anime. Other authors mention two fubftances to which this name is given, one of which is brought from India, and is refinous: the other is brought from Brafil, and is fimilar in appearance and infolubility in fpirit of wine, or in water, to the fubftance called gum copal. All the anime which is to be found in thops of druggiits is of this latter kind ; and if it does not praceed from the fame tree as gum copal, is fcarcely diftinguithable from it. (z) Anise. The outer thin fkin of the feeds of this plant contains an eflential gil, and the kernel itfelf contains an inodo- rous, infipid, expreflible oil. Newman. a) AxxotTO is a red mafs extradited by infufion in water, and fermentation from the pellicles of the feeds of an American tree. Lo water this mafs gives only a pale brownith-yellow color, and 1s very little foluble in that liquid. It readily diffolves in {pirit of wine, and gives a bright orange color: hence it is ufeful as an ingredient in varnifhes and lacquers. By alkaline falts it is ren- dered foluble in water, without any change produced upon its color. ANTIMONY. ANTIMONY. Antimony is a mineral of a metallic, fhining, leaden color, the mafles of which have no deter< minate figure, but are compofed of long, brittle, parallel needles, It is compofed of a femi-metallic fubftance called its regulus, united with fulphur, as moft metallic fubftances are in their mineral ftate. There are two kinds of antimony, namely, that which is called native or mineral, and is in the fame ftate as when it is dug out of the earth; and fufed antimony, fo named, becaufe it has been actually fufed in order to feparate it from adhering ftones and earths. This operation, which ought rather to be called liquation than fufion, confidering thefe words in their metallurgic fenfe, is made in great perfection upon the grounds whence antimony is dug. The procefs is very fimple and eafy. It confifts in placing the mineral in earthen pots, pierced in their bottoms with fmall holes. Thefe pots are placed in a furnace, where they receive the neceflary heat for the fufion of the antimony. As it is very fufible, (for it melts before it is red) this degree of heat is much lefs than is neceflary for the fufion of the earthy and ftony matters mixed with it. The antimony thus melted runs through the holes at the bottom of the pots, and is received in other pots placed below, and defended from the heat as much as is poffible. The antimony is allowed to cool and fix in thefe receivers, from which it therefore takes its form of cakes, in which it is fold. The countries which furnifh moft antimony are Hungary and Auvergne, whence the names Hungarian antimony, and Auvergne antimony. An- timony is alfo found in other countries, and in different forms; upon which fubje@ confult the article ORE of AN- TIMONY. As many remedies of great confequence are prepared from antimony, and as alchemifts have fuppofed it effential to the great wark, a very great number of chemical operations have been made upon this mineral, the refults of which are dif- tinguithed by particular names. We fhall here give a fum- mary account of thefe operations, and thall make references for the particular details and explanations, color. Wool and filk boiled in this folution acquire a deep, but not durable orange dye. Its colour is not changed by alum or by acids ; but is difchargad by foaps, and is deftroyed by expofure to air. It is faid to be an antidote to the poifonous juice of manioc, or caflava, The. ANTIMONY The metallic part of antimony is dj y is difengaged from i - Jhar by feveral methods. The firft and at DT : mmealy called Calcination of Antimony, It confifts ing crude antimony, grofly powdered, i fhallow earthen veffel, to the &i oe NE a] being taken to ftir J conte a uamelinepss {tis nitantly. During this calcinati the fulphur, being lefs fixed thas NCTE peo) J n the metalline part, is gra- ually, evaporated. The calcination is OE dill re florea) phuisous Vapors Jiseq What remains after the cal- : metallic part of the antimony fi the mineral fulphur, and even depri rn from t fulphu d of part of i mflammable principle. This Sr ro and lefs fufible than antimony. b ey vmod : fe in general Hi earths are fo much more fey ooh a } more efs fufibl | Sepiineg * Fe of ip inflammable elicipla: he alle ix of Antimony. It is of a grey ath col : sien itsinglly it is Yolen he ft Pinecone i mony is not poflefled ‘of thefe - ualities, b its ple earth is inveloped by Sigs; nd a re € rms of its properties. | Moro x of antimony, expofed to a great heat i i Ra SRP hen cold a hard, ELEN, r mafs, 1s melted matter is fometi : rent, and of a more or lefs dee a fen : p hyacinthine color. i Pe called Glafs of Antimony, becaufe it has the ” Fe . and properties of a vitrified fubftance. ? e ometimes calx of antimony, when fufed and cooled, be- comes an opake b 1 / yr p rown mafs, It is then called Liver of Thefe differences ! proceed from the greater or lefs qua Sy nm bls principle which remains united vies ro of the antimony. They confequentl on “i bengh and accuracy of the rio y depend en this calcination has been flich i : | ght, and much inflam- able enatier remains united with the earth of tier Shans e calx preduced is capable of melting with lefs WA, Ae he Refund 1s liver of antimony, which ought to be con : i an int i i itrifi i mas ermediate matter betwixt the vitrified and If the calcinatoin h as been more complete, th i of more difficult fufi Bn bfnce ult fufion, and the refult from it is a vitrified aftly, if the calcination has b ial) e on has been as as perfect as is pof- fible, the remaining calx is ftill more rol ints and is po incapable of fufion and vitrification. j The = § A A A aa IIIT IE ———_——_—— ANTIMONY The calx, the liver, and the glafs of antimony, are vio- lently emetic. The phenomena which they thew when treated with chemical agents; are fo much more fimilar to thofe exhibited by the regulus of antimony, as they ap- proach more to the reguline ftate, that is to fay, as they are more perfedtly deprived of mineral {ulphur, and lefs de- prived of their inflammable principle. ; Thefe three preparations of antimony being treated in clofe veflels, and fufed with matters capable of furnifhing phlogifton, fuch as the black flux, are reduced not into an- timony from which they were originally produced, but inte a femi-metallic, hard, brittle fubftance, of a dull white color, and compofed of fhining facets. This fubftance 1s called Regulus of Antimony. The caufe of this change is, that by calcination this mineral is deprived of all the ful- phur which is found united with its femi-metallic or regu- line fubftance, and that this fulphur is not reftored to it in the redu@ion above-mentioned. If then it be intended to reftore the properties of antimony to its calx, liver, glafs, or regulus, it ought to be ‘combined by fufion not only with phlogifton, but alfo with a proper quantify of mineral fulphur. Antimony may be difengaged from its fulphur, and at the fame time reduced either into regulus, liver, or white calx entirely deprived of its phlogifton, by feveral other pro- cefles, much fhorter and more expeditious than calcination, which is always very long. 3 If a mixture of four parts of crude antimony pulverifed, three parts of tartar, and one part and 2 half of nitre, be projeéted at different times into a large red-hot crucible, pt furrounded with burning coals; and when the detona- tion is finifhed, the fire raifed fo as the matter {hall be fufed ; then upon breaking the crucible when cool, a mafs is. found confifting of two diftinét fubftances, and which may be feparated from each other by the ftroke of a ham- mer. The lower fubftance is the reguline metallic part, and is called Regulus of Antimony. The fubftance lying above this is called Scoria 7 the Regulus of Antimony. "This {coria is alkaline and. acrid : it attracts the moifture of the air, and is compofed, 1. Of the alkalis of the nitre and of the tartar alkalifed by each other in the operation; 2. Of a portion of the fulphur of the antimony, which during the operation united with the alkali and formed a liver of fulphur ; 3. A portion of reguliné {fubftance of antimony diffolved by this liver of fulphur ; 4. Laftly, fome dis ar ANTI'MONY tartar which was formed by a part of the acid of the fulphur combining during the detonation with the fixed alkali. From the folution of the fcoria of the regulus of antimo- tty in water, a yellow reddifh matter is depofited in a cer- tain time, which is nothing elfe than a part of the fulphur and of the regulus of antimony which quit the alkali with- out feparating from each other; confequently it is a kind of Kermes. When the folution of this fcoria is faturated with any acid, a pretty large quantity of reddifh matter is precipitated, which is compofed, like the former, of ful- phur and reguline parts. This matter is called SULPHUR (GOLDEN) of ANTIMONY, which fee. Thefe two precipitates, and particularly the latter, are very emetic, although in them the reguline part is, (as in antimony, which has no emetic quality) united with a large portion of fulphur. The true reafon of this difference is, that in crude antimony the fulphur is much more intimate- ly and ftrongly united te the femi-metallic part than it is in the golden fulphur. Moft metals, as iron, copper, tin, lead, and filver have a greater affinity to fulphur than the regulus of antimony has. Hence this regulus may be precipitated in fufion, and its fulphur may be feparated by means of thefe metals. The regulus thus obtained is called the Regulus of the Me- tals. The name of the particular metal employed to make this precipitation is added. Thus it is called, the Regulus of Tin, the Regulus of Copper, the Martial Regulus, accord- ing to the metal ufed in the operation. Iron is moft fre- quently employed to make this regulus, becaufe of all me- tals it has the greateft affinity to fulphur, and for that reafon feparates moft eafily and perfectly the reguline part. See REGULUS of ANTIMONY (MARTIAL). If inftead of detonating antimony with a fufficient pro- portion of nitre to obtain the regulus, equal parts of thefe two fubftances are employed ; then, after the detonation, no regulus will be found at the bottom of the crucible, but by il opake, brittle mafs, of no metallic appear- ance ; in a word, fimilar to that mafs which is obtained b melting the calx of antimony alone, when too little de- phlogiflicated to be capable of vitrification. This mafs is, properly fpeaking, the fubftance called Liver of Antimony, from its color, which fomewhat refembles that of the liver of animals. By this procefs the liver is always made in fmall chemical laboratories. But it is faid that in Holland, where many chemical operations are objells of manufac- tyro SA eee mages | | | { 1 i i | 1 il ANTIMONY ture, the liver of antimony is made by melting the calx of this mineral alone, fufficiently dephlogifticated. The liver of antimony prepared by either of thefe methods is a violent emetic and purgative. Several difpenfatories require it to be employed in the preparation of emetic tartar: See this _ word. It is alfo ufed to purge horfes. When in this operation of liver of antimoa by nitre; the matter has been well fufed, it is obfervable that the. mafs found upon breaking the crucible is compofed of two diftin¢t fubftances.. The liver of antimony, being the heavier of the two, is at the bottom ; and above it lies a lighter and more faline matter, called the Jeoria, which may be feparated by a hammer. This fcoria is nearly of the fame nature as that of the ordinary regulus. It is very acrid and alkaline, and contains vitriolated tartar, and liver of fulphur, by which fome liver of antimony is kept dif folved. A golden fulphur of antimony may be alfo preci- pitated from this fcoria by any acid. When in theoperation of the liver of antimony, the fufion has not been fufficient, or the mixture has been cooled too fuddenly, then the fcoria remains mixed with the liver of antimony, which it in fome meafure keeps diflolved. Laftly, in detonating antimony with thrice its weight of nitre, after the operation, a mafs perfectly white and void of color is found. This mafs is a mixture of calx of anti- mony with certain faline matters. Thefe are, 1. Nitre alkalifed by the phlogifton of the fulphur, and of the re- gulus of antimony ; 2. Vitriolated tartar, proceeding from a portion of the acid of the fulphur, combined with the alkali of the nitre ; 3. A portion of nitre undecompofed. As to the calx of antimony obtained by this operation, it is perfetly white, becaufe entirely deprived by nitre not, only of all the mineral fulphur, but alfo of its own phlo- ifton. 2 This calx well wathed, fo as to be cleanfed from the falts, is called Diaphoretic Mineral, Diapharetic Antimony, - and White Calx of Antimony. It is neither emetic nor purga- tive; for which reafon a diaphoretic quality has been at- tributed to it, The white calx of antimony is not foluble in acids. It is exceedingly fixed, and often refratory, being capable of fuftaining the greateft violence of fire without vitrifying . or melting. All thefe properties, fo different from thofe of the regulus, the liver, and the glafs of antimony, proceed from its being entirely divefted of phlogifton by nitre. + e ANTIMONY The quantity of nitre employed in this operation is more than fufficient to dephlogifticate entirely all the earth of the antimony, fince in the {coria is found fome nitre undecom- pofed, becaufe there was not phlogifton enough in the anti- mony for that purpofe. 0 hefe phenomena of the calcination of antimony, which are conformable to thofe of all other metallic calcinations, prove in a fatisfaCtory manner, that metallic matters owe their volatility, their fufibility, and their folubility in acids to their phlogifton. The mafs remaining in the crucible after the detonation, in the operation of diaphoretic antimony, and which confe- quently contains the calx of antimony and the falts refult- ing from the operation, receives aperitive, and even purga- tive qualities from the falts contained in it. It is called Unwabed Diaphoretic. It forms alfo the fubftance called the Refolvent of Rotrou. hen the refult of the detonation of diaphoretic antimony is wathed, in order to cleanfe it from the falts, the water diffolves not only the faline matters, but alfo the fineft part of the calx of antimony adhering to thefe falts. ‘This matter feparates and precipitates in form of a very white and fine powder ; for which reafon it has been called Peari- Matter. It has alfo been named the Cerufs of Antimony, and very improperly the Fixed Sulphur of Antimony. For it is evident from the nature of the operation, that no fulphur can remain in it, nor even any inflammable matter. The pearl matter alfo gives no marks of fulphur contained, and has abfolutely the fame properties as diaphoretic antimony ; and if ie differs in any thing, it is in being more perfeitly cal- cined. "The white calx of antimony and the pearl-matter may be reduced into regulus by fufion in clofe veffels, with a re- ducing flux, as black flux, but only in part, and with con- fiderable lofs. In all thefe operations, where antimony is expofed to a fufing heat, a confiderable quantity of volatile matter rifes in {moke, and adheres in form of 2 meal or fine powder to any cold body it meets. This is called Flswers of Antimony, which are nothing elfe than the femi-metallic part of the antimony, more or lefs deprived of the fulphur and phlogif- ton ; but never entirely of the latter ; and they are therefore violently emetic. In the chemical operations for procuring thefe flowers, only antimony itfelf or its regulus are employed. For this 3 purpofe A SER i 5 3 WT St Ha a So EE NT H—— ho ners tng am SCE PE ee reer LH Re ANTIMONY purpofe a convenient apparatus and veflels are ufed: Sé FrLowERs of ANTIMONY, and FLOWERS of REGULUS of ANTIMONY. : ky When crude antimony is boiled in a lixivium of fixed alkali, a liver of fulphur is formed from the combination of this alkali with the fulphur of the antimony, by which the metalline part of the antimony is diffolved. But the alkali, by its being diflolved in water, having but 2 flight union with the fulphur, this antimoniated liver of fulphur cannot be kept fufpended in the water, when the heat of that fluid is lefs, or much lefs than is fufficient to make it boil. Hence when the liquor cools, it becomes turbid; and a brick- colored fediment falls down, which has been called Kermes Mineral. This precipitate drags down along with it, accord- ing to a general rule of all precipitates, a portion of the alkali by which it was kept diflolved. But this portion of alkali is very fmall. For this reafon alfo the kermes cannot be kept difblved but in very hot water. Hence it appears that kermes is nothing but an antimoniated liver of {ulphur, containing the fmalleft poflible quantity of alkali, or a fuperabundant quantity of fulphur and regulus of anti- mony. : Kermes may alfo be made by fufion, that is, by melting in a crucible dry alkaline falt and crude antimony, and then diffolving the combination in boiling water. The fame phenomena appear, as in the preceding operation, and for the fame reafons. a ; Kermes is a preparation of great utility and importance in medicine. See the details, the preparation of Kermes, and the theory of it more extenfively, as well as its medicinal virtues, at the article KERMES MINERAL. ; Acids difficultly diffolve regulus of antimony. "To diffolve it by the vitriolic acid, the fame procefs muft be ufed as in the folution of mercury by this acid for the preparation of turbith mineral : that is, to employ a very concentrated acid, and to diftill in clofe veflels. The fame phenomena alfo occur in this operation as in that for turbith mineral: a very fuffocating fulphureous acid rifes ; and as Mr. Geof- froy obferves, a true fulphur fublimes, and adheres to the neck of the retort: a white faline tumified mafs remains in the veflel. When the veflels are unluted, a white fume iffues like the fmoking fpirit of Libavius. Thefe pheno- mena of the produétion of volatile fulphureous acid, and of concrete fulphur, are evidently effects of the sosibingtion 0 —— ANTIMONY of the vitriolic acid with the phlogifton of the regulus of antimony. x The nitrous acid does, properly fpeaking, only corrode and dephlogifticate the regulus of antimony, which it con- verts into a white calx. It diffolves a irtle better this* reguline part, when it is applied to the antimony itfelf. - ‘This folution, as Mr. Geoftroy obferves, acquires a blueith greenith color. When only a fufficient quantity of acid is employed, it may be feen to infert itfelf betwixt the ftriz of the antimony, and there form {mall cryftals. Marine acid does not fenfibly act upon antimony nor its regulus. It only detaches from the antimony, in lumps, fome light and fulphureous flocks. Aqua regia moft direétly and completely diflolves regulus of antimony. For this operation, it is proper to employ an aqua regia compofed of four parts of fpirit of nitre, and one part of fpirit of falt. This menftruum is digefted in a fand-bath with a gentle heat upon bits of regulus of anti- mony, which are added fucceflively, fo that one fhall not be added till the former are diffolved. By means of this management, directed by Mr. Geoffroy in the Memoirs of the Academy of Sciences, aqua regia’ can diffolve about a fixteenth part of its weight of regulus of antimony. This folution has a beautiful golden color, which difap- pears by the evaporation of white fumes continually rifing from it. The aqua regia above defcribed is alfo very proper to diffolve the reguline part of the crude antimony, and the folution even fucceeds better in this way. This is appli- cable to all the folvents of the regulus of antimony. The combination of marine acid with regulus of anti- mony, which fucceeds fo ill by applying this acid directly to the femi-metal, may be much better made by employing a marine acid previoully combined with mercury in corro- five fublimate. When regulus of antimony or powdered crude antimon is mixed with corrofive fublimate, and this mixture diftilled, the marine acid, having a ftronger affinity with regulus of antimony than with mercury, quits the latter metallic fubftance to unite with the former; and from this a com- bination refults which paffes in diftillation, and has a buty- raceous appearance. It is a very corrofive metallic falt, and is called the Butter of Antimony. When the regulus is employed to make the butter of anti- mony, the mercury is feparated from the acid of the cor- Yor. I, K rofive ANTIMONY ; rofive fublimate, and pafles over in its metallic and fluid ftate towards the end of the operation, and when the fire is creafed. ; ; But if antimony has been employed to make this butter, a cinnabar may be fublimed, by increafing-the fire after the butter of antimony has paffed over in diftillation. This cinnabar refults from the union of the fulphur of the anti- mony with the mercury, and is called Cinnabar of Antimony. See BUTTER and CINNABAR of ANTIMONY. eT Butter of antimony is then the refult of a combination of the metallic part of antimony with marine acid in its higheft degree of concentration, and is therefore a powerful cauftic. It may be rendered liquid by a {mall quantity of water; but if diluted with much water, then the greateft part of the regulus feparates from the menftruum, and precipitates in the ftate of a white powder, which has been called Powder of Algaroth, and Mercury of Life. See thefe words. The powder of algaroth is a very violent emetic. Mr. Beaume has afcertained, by very accurate experiments, that when it is fufficiently wafhed it does not retain a particle of marine acid. : i The liquor in which the powder of algaroth is precipi- tated contains all the marine acid of the butter of antimony, with a portion of the reguline part, which may be feparated from it by precipitation with an alkali. This liquor has been named Philofophical Spirit of Vitriol; which name is improper, fince it contains no vitriolic acid. ; Nitrous acid poured upon butter of antimony diffolves it eafily, and even violently. When this folution has been made gradually and cautioufly, a tranfparent folution is ebtained impregnated with much regulus of antimony. As in this operation the added nitrous acid forms with the marine acid, already united with the regulus in the butter of antimony, an aqua regia; and as aqua regia is the beft folvent of this femi-metallic fubftance, a new folution takes place by the addition of this nitrous acid, entirely fimilar, as to its concomitant phenomena, to the folutions of metals by this acid, not previoufly diffolved by any other. This new folution is even fo impetuous, that when the quantity of matter is confiderable, itis apt to be thrown violently ut of the containing veflels. : ; Beit of tA Iey is entirely changed by its union with nitrous acid. This acid, as is ufual, feized upon the in- flammable part of the regulus of antimony which the marine had left unchanged : it diminifhes the adhefion of the ay ANNEAL acid with the regulus. Hence it happens that this new combination of regulus of antimony with the acids of aqua regia, when dried and calcined, no longer poflefles the volatility of the butter of antimony. Inftead then of fub- liming or paffing in diftillation without decompofition, as the butter does, the new compound refifts the action of fire, is decompofed, lets its acids cfcape, and remains in the ftate of a white powder. If frefh nitrous acid be twice poured upon this white powder, and each time the matter evaporated and calcined, the regulus of antimony is then reduced to a white earth fubftance, indiffoluble in the nitrous acid, entirely fixed and unfufible, and poflefled of no emetic or purgative qua- lities. This preparation has been called Bezoar mineral. = See this word. | This operation is one of thofe which proves moft fenfibly the power of the nitrous acid to calcine metallic fubftances, by depriving them of their phlogifton.It alfo proves that it is chiefly by means of this phlogifton that the nitrous acid diffolves thefe fubftances, fince it cannot diffolve bezoar mineral, diaphoretic antimony, nor any other fimilarly de- phlogifticated metallic fubftances. ANNEAL. Annealing confifts in making metals red- hot which have become hard and fff by frequent percuflion, or by a ftrong compreflion, in order to reftore their formes malleability and tra&ability. All metals have the fingular property of becoming more or lefs hard, untraltable, and unmalleable, after they have been ftruck fome time with a hammer. It feems as if fomething happened to them fimilar to the effect produced by the tempering of fteel. Metals thus affeted become more elaftic than before, but, at the fame time, more brittle. They are more fenfibly affeéted in this manner, in proportion as they are naturally harder. Copper is fo much affe@ed, and even gold and filver, by hammering, that they foon ceafe to be malleable, and are apt to {plit and crack, inftead of being extended, under the hammer. This labor therefore muft be often interrupted, to {often and reftore malleability to metals. This is effected by making them red-hot, which the workmen call annealing. Thus heat produces the fame effe® on metals in the ftate defcribed, as it does upon tempered fteel : for if the hardeft tempered fteel be made red-hot, and cooled flowly, it be- comes as tractable and duile as the fofteft iron. There is alfo an annealing for works made of glafs, It confifts in placing them, while newly made and ill hot, in K 2 an. AQUA-FORTIS an oven or furnace, where they very flowly cool. This annealing for bottles and other glafs utenfils is quite necef- fary to render them ferviceable ; for all glafs which is cooled fuddenly is liable to be broken, not only by the leaft change of heat and cold, but even by the flighteft force. i APYROUS. This word is applied to denote that property of fome bodies, by which they refift the moft vio- lent fire without any fenfible alteration. Apyrous bodies ought to be diftinguithed from thofe which are ofradior), Refractory fubftances are thofe which cannot by violent heat be fufed, whatever other alteration they may {uftain. But ‘a body, properly fpeaking, apyrous, can neither be fufed by heat, nor can undergo any other change. Hence it follows, that all apyrous fubftances are alfo refra&tory, but that every refraCtory fubftance is not apyrous. Very pure calcareous ftones, for inftance, are refractory, becaufe they never melt without addition of other fubftance: but they are not apyrous ; becaufe by fire their weight is confiderabl diminithed, the adhefion of their integrant parts is rd. and all their eflential properties are changed by their con- verfion into quicklime. On the contrary, a very clear and pure diamond is apyrous, becaufe the ftrongeft Ae is inca- pable not only of melting it, but alfo of producing upon it any other fenfible alteration; fo that a diamond which has been a long time expofed to the moft intenfe heat, is found to be the fame in all refpects as it was before. (4) Perhaps there is no body in nature efentially and rigo- roufly apyrous. This too is very probable; but it is fuffi- cient that there be bodies apyrous relatively to the degree of fire which art can produce, to entitle them to that name. AQUA-FORTIS. Aqua-fortis is 2 name given by artifts and manufacturers to nitrous acid, from its diffolving power. As it is not the concentrated and fmoking nitrous acid which is employed in the arts, it feems that the name aqua-fortis may be retained for that acid which has not thefe foatisles Moft artifts who ufe nitrous acid, call the purer and ftronger kind, which is alfo confiderably dearer, by the name of Spirit of Nitre. For the properties of this acid, fee Acro (Nitrous); and for the diftillation of it, fee SPIRIT of Ni1RE. (6) Some late experiments have fhewn that diamonds may be entirely diffipated or evaporated by heat, and are therefore not entitled to be ranked amongft apyrous f{ubflances. See Dia- MON DS. In AQUA-REGIA . In the manufa&ure of foap, the cauftic alkaline lixivium is called alfo the flrong water, or foap-lees, or lixivium of foap-boilers. See Lixivium. AQUA-REGIA. Aqua-regia is a mixture of the nitrous and marine acids. Thefe two acids are mixed to obtain a menftruum capable of ating upon certain bodies which no pure acid can diffolve, or but imperfectly; par- ticularly gold and platina cannot be diflolved in their aggre- gated ftate by any other acid than by aqua-regia. Tin and’ regulus of antimony are better and more eafily diffolved by aqua-regia than by any other acid. This menftruum may be made either by merely mixing the fpirit of nitre with fpirit of falt, or by diffolving in fpirit of nitre a falt containing marine acid, and particularly fal am- moniac and comman falt. Laftly, it may be well made by diftilling nitrous acid from either, of thefe falts; becaufe: nitrous acid, being capable of difengaging marine acid from thefe falts, does altually difengage it, either by fimply dif- folving them in nitrous acid, or by diftillation. The only difference betwixt the feveral forts of aqua- regia, prepared in thefe different manners, is, that the aqua-regia made by merely diffolving fal ammoniac or com- mon falt in nitrous acid contains ammoniacal or cubic nitre, and that thefe neutral falts do not exift in the aqua-regia made by mixture of the two acids, or by diftillation. The prefence of thefe neutral falts in aqua-regia does not injure its diffolving powers. Accordingly, as the aqua-regia which contains them is the eafieft prepared, and leaft ex- penfive, it is more generally ufed than the others. But it is neceflary to obferve, that the ammoniacal nitre in the aqua- regia may occafion confiderable differences in the nature of the precipitates made from folutions of metals in this men- ftruum, by feparating from thefe precipitates any of thofe metallic fubftances which it is capable of diflolving, and alfo by a portion of it adhering to precipitates. For in- ftance, gold precipitated by a fixed alkali from an aqua- regia made by mixing the pure nitrous and marine acids, does not fulminate; whereas it does fulminate when pre- cipitated from an aqua-regia made by diflolving fal am- moniac in nitrous acid. See PRECIPITATES; and GoLD (FULMINATING). 3 The mixture of the nitroys and marine acids prefents a very fingular and remarkable phenomenon; which is, that the vapors of this mixture are more expanfive and more difficult to be confined than the vapors of either of the acids K3 before AQUA-REGIA before mixing. This proves a re-aétion of thefe acids upon ‘each other. This phenomenon is very little fenfible when the acids employed contain much fuperabundant water ; but 1s more manifeft in proportion as thefe are more concen- trated. I have obferved, that upon mixing moderately fmoaking nitrous and marine acids, which had remained without accafioning any difturbance in their bottles, an aqua-regia has been formed infinitely more {moaking, and which has made the flopper fly out of the containing bottle, particularly in weather fomewhat warm. Mr. BD when diftilling a pretty ftrong nitrous acid upon fal ammo- niac, obferved, that the vapors which pafled were fo elaftic, that notwithftanding every precaution that could be taken in fuch a cafe, it was impoffible to continue the diftillation, - As to the proportions of nitrous and marine acids, or of fal ammoniac, which ought to be employed for the prepara- tion of aqua-regia, there are no eftablifhed rules, Se aqua-regia is made by diffolving four ounces of fal ammoniac in fixteen ounces of nitrous acid. But thefe proportions ought to be varied according to the nature of the folutions intended, To diffolve, for example, the greateft poffible quantity of platina, the beft proportion is equal parts of the two acids. To difiglve the greateft quantity of regulus of antimony, the aqua-regia ought to be compofed of os parts of nitrous acid to one of marine. In general, the greater the proportion of marine acid, or of fal ammoniac, is in aqua-regia, the lefs are the imper- fect metals, and particularly tin calcined and precipitated by it. An aqua-regia, compofed of two parts of fpirit of nitre and one part of {pirit of fal ammoniac, makes a clear folution of nearly an equal weight of tin, without forming any precipitate: but for this purpofe, the operation muft be performed, flowly, and heat muft be avoided as much as pofiible, See Gorp, PraTina, TiN, and REGULUS of ANTIMONY, (c) AQUA- (c) Aqua regia does not diffolve filver ;: but when the quan. tity of marine acid contained in the aqua-regia is very fmall, the “acid of nitre does then diffolve filver, which is immediately after- ‘wards attacked by the marine acid, with which it forms the metallic falt called Jung cornea, and is precipitated. Aqua-regia diffolves a larger quantity of lead than marine acid. All the other ARBOR-DIANZE AQUA-SECUNDA. This is nothing elfe than aqua-fortis diluted with much pe water.” It is employed in feveral arts to clean the furface of metals and of certain {tones, and for fome other purpofes. AQUA-VITZA. Aqua-vite is the f{pirituous part obtained by a firft diftillation from wine, or any.other liquor which has undergone the vinous fermentation. It is, pro- perly fpeaking, ardent fpirit, or {pirit of wine. o make the aqua-vitz that is fold in commerce, wine is put in large copper alembics or {tills, to which worms are fitted, and the diftillation is fo conducted that the liquor flows out of the beak of the {till in a conftant ftreain, and is continued till the liquor begigs to be no longer inflam- mable. - It is evident that this diftillation, being haftily and un- artfully performed, can only furnifh a very impure fpirit of wine, mixed with feveral of the other principles of the wine employed. Thus aqua-vite contains much fuper- abundant water, and much oil of wine, fubftances entirely foreign to what is properly called {pirit of wine. Thefe heterogeneous matters contained in aqua-vite pre~ vent it from being employed in chemical operations. To purify it, and change it into {pirit of wine, it muft be again diftilled and rectified. See SPir1T of WINE, AQUILA ALBA. (d) ARBOR DIANZA. The arbor Dianz is the refuilt of a chemical operation, by which particles of filver, pre- vioufly diffolved in nitrous acid, are capable of arranging themfclves in the form of a fhrub. Chemilts have called this Arbor Diane, from the filver which they alfo call Diana, or the Moon. The following procefs given by Lemeri for making the arbor Diane fucceeds well : « Take an ounce of fine filver, diffolve it in a fufficicnt “ quantity of fpirit of nitre, very pure and moderately ftrong : mix this folution of filver in a matrafs with other metals it perfe&tly diffolves. According te Geliert’s Table, “the fubftances which aqua-regia diffolves are placed in the follow. ing order, beginning with thofe to which it moft powerfully unites; Phlogifton, zinc, iron, regulus of cobalt, copper, tin, arfenic, bifmuth, mercury, lead, regulus of antimony, gold. In this table copper is erroneoufly placed before tin, as the later metal readily precipitates the former. (4d) AQuiLa ALBA is a name given to fweet mercury. See MERCURY (SWEET). XK 4 about eT v ! a a ; Ba Aa— . ARBOR-DIANZE ¢¢ about twenty ounces of diftilled water ; add to this mix- €¢ ture two ounces of mercury, and let the whole remain “ at reft. During a fpace of about forty days, a kind of filver tree will be performed upon the mercury, with ¢ branches refembling vegetable ramifications.” As this procefs is very long, we thall here add another much thorter, taken from a memoir of Mr. Homberg, and quoted by Mr. Baron, in his edition of Lemeri’s Che- miftry, od Make an amalgam without heat, of four drams of filings of filver, or, fill better, of filver-leaf, and of two drams of mercury (See AMALGAM); diffolve this amalgam in four ounces, or a fufficient quantity, of fpirit of nitre pure and moderately ftrong ; dilute this folution in about a pound and a half of diftilled water ; % thake the mixture, and preferve it in a bottle with a glafs- ftopper : when this preparation 1s to be ufed, an ounce “ of it is to be put into a phial together with about the ¢ fize of a pea of an amalgam of gold or of filver, which ¢¢ ought to be foft as butter; and the whole is to remain ““ at reft: foon afterwards, fmall filaments are to be feen ifluing from the fmall amalgam, which quickly encreafe, “« branch out on both fides, and take the form of thrubs.” This ‘experiment, which is enerally confidered merely as curious and amufing, is fra on many of the effential properties of the fin Batces employed. As mercury has a ftronger affinity than filver to nitrous acid, it obliges this metal to feparate and precipitate. But in this precipitation there are two eflential particulars : the firft is the color of the filver precipitated, which on this occafion appears in Its natural form and metallic brilliancy. The caufe of this 1s, that it was precipitated by a metallic fubftance; for it appears, that in general this happens whenever one metal 1s precipitated by another metal; whereas metals precipi- tated by any other fubffance are always in form of calxes, or earthy precipitates, without any metallic appearance. See PRECIPITATION. The fecond remark to be made on the precipitation of filver in this experiment is, the fincular arrangement taken by the particles of filver on the furface of the mercury one after another, according as they are feparated from the nitrous acid. We cannot but perceive in this phenomenon a very fenfible effect of the attraétion or affinity of the in- tegrant parts of the fame fubftance, or of two fimilar fub- ances to cach other, In fad, it can only proceed from this €C 144 << << “4 we ASBESTUS: (#) © ob ld oh ASHES. . This name is generally dpplied ‘to the fii flance remaining of bodies ‘containing ‘an inflammable matter, of which they have Been: deprived by burning, or calcination: in open air. Thus workmen, without under- ftanding ‘ chemiftry, and mduced merely by analogy “of refemblanee, apply the naive of afbes to metallic earths thus calcined. Pewterers, for example, give the “hame Tin-ajbes,, to the earth of tin which in fiifion: nd deptived of its phlogifton and metallic properties. If workmen. had always. applied names as properly ‘as they ‘have done “this, they ¢ould not have been: blamed. See CoMBOSTION. . ASH-HOLE. The ath-hole is the loweft part of z furnace, and is intended to receive the athes falling from the fire, and to give a paflage to the air which is to be intro- duced into the furnace, to keep up the combuftion. Su URNACE. CATHANOR. Chemifts have diftinguiflied by this name a furnace fo conftruced ‘that it can always maintain an equal heat, and which fhall 1aft a long time without addition of frefh fuel. Fhe holy of the athanor has nothing in it particular, and is conftrulted like ordinary furnaces. But at one of its fides, or its middle, there is an upright hollow tower, which. communicates with’ the fire-place by one or. more floping openings. “This tower ought to have a lid which exactly clofes its upper opening. a 1733) propofes to make a varnifl for fhips, of arfenic with pitch, fulphur, or rofin, to preferve the timber from rotting, aud from worms. (i) Asa-roeTiDa is a gum-refin, from four ounces of which: rectified {pirit is capable of extracting two ounces fix drams and a. half of refinous extraét ; and water,. one ounce three feruples and 2 half of gummy extra. Four ounces of afafcetida, diftilled either with water or with {pirit, yield above a dram of effential eil, in which its peculiar fmell refides. Newman. (%) AsBestus is a grey, greenith or blackifh ftone, poflefled: of the fame chemical properties as amianthus, and is therefore: referable ta the fame clafs of earths. See AmMianTHUS. The chief differences betwixt thofe two {tones are, that afbeftus is heavier than amianthus, and its fibres are more hard and brittle.. Falfe afteflus is a name given to plume-alum. See Aru PLume). ’ pe When AURUM MOSAICUM When the athanor is to be ufed, as much lighted coal is put in the fire-place as is judged neceflary, and the tower p filed to Bs top with Y ohicd fuel. The tower is then to be exaétly clofed with its lid. As faft as the coal in _ the fire-place is confumed, that in the tower falls down and fupplies its place. As the coal contained in the tower has no free communication with the external air, it cannot burn till it falls into the fire-place. i The athanor being much celebrated and ufed by ancient chemifts, it has been particularly defcribed by many authors, and was formerly found in all laboratories. At prefent this furnace is much lefs employed, and is even neglected. The reafon of this is, that all the ancient chemifts were in fearch of the art of making gold ; and being excited by this power- ful defire, and confidence of fuccefs, they fpared no trouble nor expence to accomplifth their defign. They undertook, without hefitation, operations which required great length of time and unremitted heat. Whereas now, thefe alluring hopes having vanithed, the cultivators of chemiftry have no other view than to extend and perfe& the theory of this effential part of natural philofophy. This motive, altho’ undoubtedly much nobler than the former, feems however to be lefs powerful over moft men. For now, all long and laborious operations whence chemiftry might receive great advantages, are negleéted, as being tirefome and difguftful. There 1s, in fact, a confiderable difference betwixt the. hope of explaining a philofophical phenomenon, and that of obtaining an ingot of gold capable of producing many others. Hence the inftruments employed in long opera- tions, and particularly the athanor, are now much neglected and alfo becaufe the fuel in the tower is apt to flick there or fall down at once in too great quantity. The Lamp-furnace, which is.a true athanor, may be fuccefsfully employed in operations which do not require much heat. See Furnace (Lamp). (7) AURUM MOSAICUM. (m) AZURE. (1) See Prate IL fig. 2. which reprefents an athanor. ; (m) Aurum Mosaicum or Musivum, or Mustcum, 1s 2 chemical preparation confifting of beautiful gold-colored flakes. It may may be prepared by the following procefs. Take of tin twelve ounces, flowers of fulphur {even ounces, of {al ammoniac fix ounces, of purified mercury fix ounces. Melt the tin and add the mercury to it, and when the mixture is cold, ‘powder it, and mix with it the fal ammoniac and {fulphur. Sublime the mixture Lz in = a eS EET er shoes i ores - . ee ei mn LER ER : ; AZ UREGT : "AZURE. The word azure, which at prefent fignifies in general a fine blue color, was formerly appropriated te Lapis Lazuli, called azure fone, and to the blue prepared from it. Butince a blue has been extracted from cobalt, cuftom has applied to it the name of azure, although it differs confiderably from the former, and is incapable of ‘being ufed for the fame purpofes, and particularly for paint- ing in oil. The former at prefent is called Lapis Lazuli, or only lapis, and the blue prepared from it for painting in oil, is called Ultramarine. The name azure is generally applied to the blue glafs fade from the earth of cobalt and vitrifiable matters. This glafs; which is called malt when in mafles, is called azure a matrafs. The avrum mofaicum will be found under the fubli- mate with fome drofs at the bottom. - = Mr. Peter Wolfe has given, inthe Phil. Tran. vol. 61. an expla- nation of the above procefs. He fays, that as foon as the mixture grows warm, the tin aéts on the fal ammoniac, and fets free its volatile alkali, which having a great affinity with fulphur, joins with a great part of it, rifes in the fublimation; and is totally diffipated : That the portion of tin which acted on the fal ammo- niac and fet free its volatile alkali, unites with the marine acid of the {al ammoniac; and forms a {alt of tin which fublimes: That the mercury, which was added only to divide the tin, unites with fome of the fulphur, and fubliming forms a cinnabar : and laity, that the remaining tin unites with the remaining fulphur, and forms the aurum mofaicum. According therefore to this explanation, the aurum mofaicum confifts only of tin and fufphur combined together; the ufe of the fal ammoniac being only to prevent the fufion ef the fulphur, and the ufe of the mercury being to divide the tin. Accordingly, the fame ingenious chemift fhews that aurum mofaicum may be prepared without mercury and fal ammoniac. He alfo obferves that not only tin, but alfo other metallic fubftances may be made * to combine by fimilar procefles with a greater quantity of fulphur than by fufion. Thus, he found that bifmuth produces a golden- coloured compound, and that iron, copper, lead, and regulus of antimony formed black mafies. Avram mofaicum bas no tafle, is unfoluble in water, or by acids, or by liquid alkalis. But by fufion with fixed alkali, it forms a yellow hepar, foluble in water. Aurum mofaicum defla- grates with nitre, as tin itfelf does. Aurum mofaicum is ufed as 2 pigment, being of a fine golden colo. r, and is alfo mixed with melted glafs to imitate the {fpangles of lapis lazuli; for which latter purpofe, fhining talk is alfo employed. : only BALANCE only when it is reduced to a fine powder. Several kinds of -, azure are diftinguifhed, according to its degrees of beauty, by the names of Fine Azure, Powdered Azure, and Azure of Four Fires. In general, the more intenfe the color, and the finer the powder, the more beautiful and dear it is. Azure is employed to color ftarch; hence it has alfo been called Starch-Blue. It is ufed for painting with colors and for a blue enamel. See COBALT, SMALT, ZAFFRE. See alfo Lapis LazuLl. TYALANCE (HYDROSTATICAL). The hy- B droftatical balance is an inftrument by which the fpe- cific gravity of bodies is determined. For this purpofe it is neceflary to find how much any given quantity of. a body, whofe fpecific gravity is required, lofes of its abfolute gra- vity when lunged into a uid. All liquid fubftances are proper to determine {pecific gravities, becaufe thefe gravi- ties are only relative : .but water has been generally em- ployed for this purpofe, becaufe it is the moft common liquid, and moft conftantly of a nearly uniform weight. a When a body is to be weighed in water, it is {fufpended to one of the arms of a balance, to the other arm of which is fixed an ordinary fcale, and in this fcale weights are to be put fufficient to maintain an equilibrium with the body fufpended in air. The weight neceflary for this purpofe is to be obferved and remembered. Then the fame body fill fufpended at the arm of the balance, and counterpoifed by the weights in the fcale, is to be immerfed in water, by which the equilibrium is deftroyed, and the balance in- clines to the fide of the weights. The weights are there- fore to be diminifhed till an equilibrium is reftored with the body funk entirely in water. The difference betwixt the weights of the fame body weighed in air and in water, determines its {pecific gravity. It is proper BE En upon this fubje&t, 1. That water can determine the fpecific gravity of bodies only which are fpecifically heavier than itfelf. For it is certain, that if _ they were lighter than water they could not fink in it by their own weight, which is neceflary for the experiment. In this cafe it is neces to employ fome liquid lighter than water, fuch as ethereal oils, fpirit of wine, or ether. "2. It is proper to remark on the fubject of the hydrofta- tical balance, that it can be employed conveniently for I L 3 folid BALLS (MARTIAL) folid bodies only, becaufe the fluids cannot be weighed in water but by means of fome veffel which muft be immerfed along with them. But this veflel haying its peculiar fpe- cific gravity would render a troublefome ¢alculation necef- fary. * Another method is then generally ufed. to determine the fpecific gravity of liquids, 3. If the folid body, whofe fpecific gravity is to be de- termined, be foluble in water, as, for inftance, a lamp of falt, water could not be employed for this experiment, be~ caufe a quantity of it would be diffolved during the time of weighing; by which an error would be occcafioned fo much ‘greater as there was more. of the foluble body dif- folved. In this cafe then it is neceflary to ufe fome other liquid which cannot diffolve the body, or elfe not to empleo the hydroftatical balance, but the fame method by which the fpecific. gravity of liquids is difcovered. See Gravity, GRAVITY (ABSOLUTE), GRAVITY (SpEcIFIC). BALLS (MARTIAL). Martial Balls are a mixture of filings of iron and of cream of tartar formed into a folid confiftence and form of a.ball, which is ufed to impregnate water or ‘other liquids with iron diffolved by the tartareous acid. To make thefe balls, one part of filings of iron and two parts powdered cream of tartar are mixed well together, and ‘put into an earthen or iron veflel with fome water. his mixture is to be flirred from time to time, till it be- comes almoft dry, and then it is to receive more water, and to be ftirred as before. ‘This treatment is to be con- tinued till it acquires, when nearly dry, fomewhat of the confiftence and tenacity of foftened rofin. Then it is to be rolled up into the form of a ball, which is generally kept tyed up in a rag, and when intended to be ufed, it is to be infufed in water, till it gives fome color to that liquid. ~The infufion of martial balls is tonic, vulnerar 5 dif= cutient, and aperitive ; and is employed both internally and externally.” See Iron, ah Iron being foluble in all acids, is attacked in this prepa- ration by the tartareous acid, which reduces it to a kind of neutral falt not cryftallizable. This falt would remain liquid, and would form a foluble martial tartar, called Tar- tarifed Tinlture of Mars. If proper proportions of filings of iron and cream of tartar be ufed, and treated long enough for an entire and complete combination, * nothing would be obtained but a liquor of magma, which ‘could not be frsleryed in a folid form, but would be continually moift. “herefore in’ the martial ball there is a good deal of the cream BALLOON cream of tartar and filings of iron not combined: together, ‘Hence it follows that the infufion of the martial ball is - entirely of the fame nature as the tartarifed: tin&ure of Mars; and therefore thefe preparations may be fubftituted for each other. See TiNcTURE of Mars (TARTARISED). BALLS (MERCURIAL). Mercurial balls are an - amalgam of mercury.and tin, fufficiently{olid-to be:mould- ed, and to preferve a given form, ° pid The method of making them is by adding mercury to melted tin, and pouring the fluid mafs inte a round and hollow. mould. jo 1.4 ] Thefe balls are employed to purify water, in which they are boiled ; for. which. purpofe travellers often: carry. fome. along swith them. : - BALLOON. This name is given to glafs bottles, or re- «ceivers, which are generally round like hollow {pheres, or like - foot-balls, called in French, Balons, whence they are named. _In a laboratory. there ought. te, be balloons: of different: fizes, capable oF containing from a quart of water to fifteen or twenty pints. Thelarge balloans are employed in diftil- lations in great, ‘being capable of containing much; and having oie enough to admit -thofe of large retorts. . For the contrary reafaus, #mall balloons are employed when a little matter is to be diftilled. : Large. balloons are al{fo neceffary when the vapors dif- engaged: during the diftillation are very elaftic and diffi- cult to be condenfed; ‘becaufe fuch vapors would not find in {mall veflels fufficient fpace to circulate and condenfe;; hence they would either burft the veilel, or if a vent was given them to prevent that accident, they would be entirely diffipated and loft. Notwithftanding the fize of the balloons employed, fo much air is difengaged during the diftillation of certain hard bodies, vegetable and animal, fuch as wood, tartar, hartfhorn, &c. and the va- pors of certain acids, fuch as the fmoking fpirits of nitre and of fea-falt, are fo elaftic and expanfible, that a fmall hole in the fide of the ballogn is frequently neceffary to to give vent to thefe vapors: Afterwards this hole, which ought to be about half a line in diameter, is to be clofed with.a peg of wood, or fome lute. : It is to be withed, that in the glafs-houfes where chemical - veflels are made, it was the cuftom SE to make fuch holes in the balloons; which might eafily be done by a pointed infirumenty while oe glafs is {till hot and foft. Tread 4 o B A'L'S A ME of this praflice, cherifts’ate themfelves obliged fo drill holes through the baloons with confiderable difficulty a; HTT cad mo yy ii. and hazard of ‘breaking. “T'hi§ “operation i¢ performed 4 the following manner. 33 26 STING AMAT SETI AT, he moft convenient part far drilling this holes riearer the neck than the bottom of the balloon, Ly bs Jote purpofe one of thofe bubbles which are always found in glafs is chofen. This bubble is firft of all cut or broke: a pointed angle of a flint, and afterwards the holé* is to be ‘completed by turning this ‘pointed : flin¢ ‘al ways "i fz 0 ited © flim ys. in the fame place. Mr. Beaumé obférves, that when ail entrylis once rialeng 1 the flint, the hole may be better finifhed by a triangular drill with a firong hard “tempered feel Solin, bicaals the angular points of the flint are Continually breaking, by" which the operation is prolonged. (n) : For: certain’ operations baHoons with two ‘necks placed oppofite to edch other are ufed. One of ‘thefe ought to be’ large enough to: receive the rieck of the'retort, and’ the" other to ‘enter ‘the neck of a fecond balloon. Thefe two. Jomings muft be ‘well luted togéther. * See Lute. oy - This ‘apparatus is called Enfiladed Balloons. Their ufe is to encreafe the whole fpace ‘of the receiver, ‘becaufe any number of ‘thefe may be adjufted to each other; and as they communicate ‘with each “other; their capacity is {3 much’ larger as their number is greafer.” But good ‘artifts feldom ufe fo troublefome “an” apparatus. The only one of thefe veflels which is generally ufed; is a fmall oblong balloon with two necks, ‘which is to be luted to the retort and to the great balloon. - It ferves to rémiove this receiver from the body of the furnace, and to hinder it from being expofed to too great, heat. Thisdmall balloon with two necks is called an Adopter. As this adopter 'is larger in its middle than at either ex-. tremity; it ferves alfo to receive folid bodies, and to prevent them Jo pallag with the liquids -into the great balloon. It is chiefly in diftillations of volatile concrete falts that the adopter ferves for this ‘laf purpofe. Ses DrsTiLLATION and RECEIVER, 1 Alia | BALSAM. By balfams are meant oily, odoriferous, and aromatic matters, liquid, but fomewhat thick, which Jn) Pierced balloons, receivers and retorts are commonly made” in Englith glafs-houfes. But as chemiits may have occafion‘to drill holes through glafs vefiels, it may be proper to obferve, that this operation may be beft performed with a copper drill. and emery, as a ftecl inftrument occafions vibrations apt to break the glafs. flow BAL SAM flow fpontaneoully from’ certain ‘trees, or from incifions made on purpofe to obtain a larger quantity. “Thefe balfams, which may more particularly be called 7a- tural ye, to diftinguifth them from fome compofitions alfo cilled balfams, derive their liquidity and fmell from a greater or lefs quantity of effential oil which they contain, and which may be‘extracted by diftillation with the heat of boiling water, Sec O1Ls (EsseNTIAL). ‘Balfams may be even confidered as true effential oils, which’ have loft fome of their ‘odoriferous principle, and of their fineft and moft volatile part. When they are deprived of their remaining part of volatile oil, their refiduums exaétly refemble thofe which remain after the re&ification of effen- tial oils. ‘Thefe refiduums are true refins, from the analyfis of which the fame principles are obtained as from natural refins; and thefe laft are nothing but balfams exhaufted by time, or by the a&ion of the air, and of the fun, of all Deir odoriferous and volatile parts. There are feveral kinds of natural balfams. They do not effentially differ from each other, but only in the fmell and degrees of confiftence. The fame kind of balfam alfo fre- quently differs with refpect to the degrees of thefe two qualities. The principal natural balfams are the balfam of Mecca, or the white Salon; which is the moft rare and dear of all ; the balfam of Tolu and of Peru in fhells, both which Mr. Beaumé confiders as the fame kind of balfam, with this difference, that the firft is liquid, and the fecond is almoft dry; the balfam of Copabu, or of Copaiba, vulgarly Capivi; liquid Slyrax, or florax ; and turpentines. See for an example of the afa- Iyfis and properties of all thefe ballon the word TURPENTINE. ~~ BALSAM of SULPHUR. The balfam of fulphur is a folution of fulphur in oil. Sulphur, from the quantity of phlogifton it contains, is infoluble in water and aqueous liquors: but it is capable of diffolying in oils, which alfo contain much phlogifton. “All “oils, either exprefled or eflential, can diffolve ful- phur: to make this folution, the oil ought to be poured on the fulphur in a matrafs placed in a fand-bath, and fufficient heat applied to melt the fulphur, according to Mr. Beaumé’s obfervation, who kept thefe two fubftances a very long time together in a lefs heat, without perceiving any fign of folution. | "While the oil is diffolving the fulphur, it acquires a reddifh or brown color, an acrid and difagreeable tafte, and | 4 a ftrong BASALTES 2 firong fetid fmell like. that of the combination, of oil with vitriolic acid. As water can diffolve only a determinate quantity, of fome falts, and as this quantity is greater when the water. is, warm, than when cold, fo. alfo oils can diflolve.only a determinate. quantity of fulphur, and this quantity. is, greater when. heat is applied : hence. it, happens, that when an oil is far turated with fulphur, b a {uitable. heat; a part. of. the. fulphur thus diffolved. LR the oil, when: the folution cools, and coagulates. at, the. bottom of - the; veffel. in a _cryftallized form, in the fame manner. as fome:falts do, - which. having been diffolved in boiling water, cryftallize on. the application of cold. ‘Lhe portion of fulphur. remaining, diffolved. in oil is ina; fingular ftate ; the adhefion of its.conflituent parts, namely, . the vitriolic acid and phlogifton, feems to. be much dimi- nithed by the union they contra® with the principles. of the oil. Its vitriolic acid unites with the watery, part of | this oil; and thus thefe two principles have no longer. the necefiary relation to each other for the formation of falphur. See SULPHUR. Mo It is certain at leaft, that all thefe changes happen. when the balfam of fulphur is diftilled. This is proved.by the. analyhs which Homberg. made of this combination : for by diftilling it with a very flow fire, he obtained a volatile {ulphureous acid, a vitriolic acid more or lefs ftrong and. {ulphureous, fome oil, partly fluid and. partly. thick, anda. charry refiduum, but no fulphur. This is a proof that the fulphur-was decompofed in the experiment, as all the fame produdls are obtained from a.combination of. vitriolic acid: with oil, when the oil is in too great quantity relatively to the acid. : : ‘The balfams of fulphur are named. from the. particular oils which enter into their compofition. Thus if,a balm of fulphur be made with the eflential oil of. turpentine, it is: called ferebinthinated balfam. of fulphur ; if it be made with. the effential oil of anifeed, itis called the balfam of fulphur with oil of anifeed. Thefe are the two moft.ufed. The. balfam of fulphur made with oil of nuts is called Rulland’s i Z Sulphur. See SULPHUR. ASALTES. (0) yn BASIS: (2) BasarTes is a heavy, hard ftone, chiefly black or green, lle BLACKNESS galled biffre, ufed for painting in water-colors. The fineft of the foot blacks is lamp-black, ufually prepared by burning in an oven the dregs and pieces of pine-bark left in the procefs for makin common rofin. Soots prepared by burning {mall pieces of oo or of mineral bitumens very {lowly under a copper pan, were found by Dr. Lewis to be not different from thofe prepared from oils and refins ; and, like thefe, contained nothing foluble in common water, as the foot collected in common chimneys does. See Soo. The black coloring materials produced by mixture are, 1. A folu- tion of green vitriol in water, added to an infufion of galls or fome way aftringent, is the bafis of black inks, and black dyes for the ufes of callico printers, tanners of leather, hatters, dyers, &c. The color given by this mixture adheres permanently to filk and wool, but may be difcharged from linen and cotton by wathing. If the water employed for diffolving the vitriol, or infufing the gatls, have been diftilled, or if it be common {pring water, or - frefth rain water, the color produced will be bluith ; and if the water has any putrid or alkaline quality, the color produced will have a purple or reddifh tinge. The blacknefs given by galls is much improved by addition of logwood. All vegetable aftringents do not produce blacknefs by mixture with folution of green vitriol. ° Thus the Peruvian bark is faid to give a greenith color. See Ink. 2. A folution of fiver in nitrous acid gives black ftains to folid white animal fubftances, to agates, and fome other ftones, after- wards expofed to the fun and air. Bones and hair at firft receive no ftain, but fooner or latter, as they happen to be more or lefs expofed to the fun and air, they become of a reddith or purplith color, which gradually changes to a brown, and afterwards to a black. Mr. Schultze (4. Natur. Curiofs wol. 1.) fays, that white chalk moiftened with folution of filver, by expofure to the fun, acquires a purplifh black color on its furface, which color may be interrupted by threads fhading parts of the chalk. If the chalk, thus moiftened with folution of filver, be dried in the fhade or by fire, ‘no color will be produced. No color was given by this method to white clay, talk, or plafter of Paris. The action of folar light alfo gives a dark color to the white precipitate of bifmuth, and to {weet mercury. 3. A black ftain is given to paper or other white fubftances by folutions of lead in acids, when thefe fubftances are afterwards expofed to phlogiftic or ful- phureous vapors. See Ink (SympaTheTIC). Calxes of lead melted with fulphur form a black or blackifh mafs ufeful for taking cafts from medals, as it is'lefs brittle than fulphur alone. Mr, Le Blon found that a black color may be produced by mixing blue, red, and yellow pigments; and Mr. Cartel direfls that fifteen parts of blue fhould be mixed with five parts of red, and three of yellow, and that each of thefe colors fhould be very deep. Dr. Lewis tried fuch mixtures, but produced only a brownifh or greyifh black, 5 BLACK- - BLACK-JACK. (z) rr BLOOD. Blood is well known to be a red liquor. in molt animals, circulating in their veflels during lite and the common fource whence all the neceflary and fuperfluous animal liquids are derived, (a) oh Blood newly drawn from a found animal. gives no fign of an acid or alkaline quality. It has a fweetith and fome- what faline tafte, When left to itfelf jt coagulates, and yuicly Fats so a Rrmentation at firft a little acid, and aiterwards entirely putrid, in the e perfectly Animalia abhi. Foe nore fl ber This liquor contains nothing volatile by the heat of boiling water, but a pure phlegm. Thus when blood is diftilled in a water-bath, it is only dried, not entirely de compofed. ‘By this drying it lofes of its weight. The refiduum being diftilled ina naked fire, yields volatile alkali and animal oil, at firft thin, and afterwards thick : in the retort a charry refiduum remains, which can difficultly be reduced to athes, from the lixiviation of which a little common falt.may be obtained. From this analyfis, which is almoft all that chemifts have done to difcover the nature of the blood, it appears that this liquor contains the fame principles as all other perfectly animalifed matters, But a more accurate exami- nation might probably be made of it by feparating at firft from each other feveral different fubftances, of which the blood is only a collection or mixture, and then by analyfing cach of thefe fubftances, as has been done with milk. In fa&, the blood being opake, or not very tranfparent, appears to be, as milk is, nothing elfe than'a mixture of feveral heterogeneous matters confounded together, without being diffolved by each other. It is known, that, when the - blood is no longer circulated in the veflels of ‘the animal, but left at reft in a veflel, it coagulates and feparates fpon- fancoufly into a red mafs, and a white liquor, or ferum, in waich the red mafs floats; and that by wathing, the red fz) BLack-Jack, or Brevp, is a mineral galena. See Garena (Favse). aan (a) The color of blood, like that of many other fubftances, is affected by expofure to air, by which it acquires a fcarlet tinge. Arterial blocd has this fearlet color, which it has acquired by pafling through the longs in refpiration. The blood flowing through the viens has a deeper and lefs vivid red color. It ac. quires the fcarlet color by expofure to air, and arterial blood lofes Hs vivid red color by exclufion from air. rely part BL OOD part of this mafs may be carried off, and the remaining matter is white and gelatinous. There are then three diftinét matters in the blood which feem to correfpond with thofe contained in milk; that is, the ferum of the blood correfponds with the whey of milk; the white gelatinous matter, with the cheefy part; and laftly, the red globules with the butyraceous fubftance. It is fo much more probable that the red part of the blood is oleaginous, as anatomifts, who have examined the blood by microfcopes, have obferved that this red part is compofed of globules fwiming in a white liquor, and as all oily matters, when well mixed, but not diflolved in a watery fluid, have this globular appearance. (J) This being eftablithed, if the blood were to be examined more exactly than it bas hitherto been, it would probably be neceflary to begin by feparating from each other the three above-mentioned fubftances, each of which ought after- wards to be fubjected to experiments and analyfes, as has been done with milk. It is probable that this method of analyfing blood would throw new light upon its nature and principles, which are yet very imperfeétly underftood, as well as thofe of other animal matters. The purely gelatinous parts of the blood are probably not different from any other animal jelly : but it is to be prefumed that fome peculiar falts might be obtained from the ferous parts, as have been from milk and from urine; and that the red globular part would be found to be oleagi- nous. The acid, or volatile alkaline principles which would be obtained from the red part of the blood would determine whether or not it is a truly animal oil, or fat, If it be true, as Mr. Homberg and Mr. Macquer affim, that fome acid may be obtained by analyfing the blood, it would probably be found to belong to this red fubftance. (4) The red particles of blood have been generally thought tq be globules. Father de Ja Torré pretends to have difcovered from his microfcopical obfervations that they have an annular form. But Mr. Hewj/on maintains that the central {pot taken by Father de la Torré ior a hole, is a folid dark-colored particle contained in the middle of a tranfparent veficle, which js flat like a piece of money, and not globular. This veficle, he fays, is Spe or filled with a fubtle fluid, and is capable of being diffofved by water, as alfo is the folid red particle, See Mr. William Hew- fon’s paper in the Philo. Tran. vol. 63. on the figure and compofis tion of the red particles of blood ; and alfo, Mr. Hewfon’s experi- ments on the blood. Phil. Tran/. vol. Go. Laftly, BLT UB Laftly, it is evident that whatever- knowledge could be acquired on this fubject by well-conducted experiments, muft extend and encreafe an interefting branch of our know- ledge, namely, that concerning animal economy. (¢) (4) BLUE. BLUE (¢) Dr. George Fordyce, in his very excellent Elements of the Practice of Phyfic, fays, that the white gelatinous matter of the blood, or coagulable lymph, continues fluid while circulating with any degree of heat betwixt 30 and 120° of Fahrenheit’s thermo- meter ; but that it is coagulated very foon after it is taken out of the body in any heat, in motion, or in reft ; and that its ceagu- lation may be prevented by faturating the blood with fea-falt, or perhaps with fome other neutral falts. The coagulum isrendered foluble in boiling water, by putrefaétion, by concentrated acids, cauftic alkalis, calcareous earths, and by fome metallic falts, He obferves alfo, that the coagulable lymph is more fluid, and is not fo eafily coagulable when the arteries of the perfon from whom the blood is drawn a& more ftrongly than they ufually do; in which cafe, the red particles and this lymph can feparate more exaltly from each other according to their denfities, the former falling to the bottom, and the greateft part of the latter forming upon the upper furface a very vifcid tough mafs called the 4uf, By putrefaction the coagulable lymph and ferum are converted into a mucilaginous matter, not coagulable by any of the methods recited above, which mucilaginous matter may be converted by further putrefaition into faline fubftances and calcareaus earth, The red part of the blood is readily foluble in water, but not in ferum, nor in a faturated folution of neutral falts, By the firft flage of putréfattion this red part of blood is broken down into {maller particles, its color is rendered darker, and afterwards it 1s converted into a mucilage foluble in ferum. From the folubility of the red particles of blood in water, it evidently appears that they are not oleaginous, as the author of the Dictionary feems inclined to believe. : (4) BLue CoLoring MaTEeRrfaLs. Concerning the blue glafs called fmalr, prepared from the ore of regulus of cobalt ; the preparation of iron called Pruffian blue; and the preparation of lapis lazuli called w/iramarine or azure, See SMaLT, AZURE and Brve (Prussian). The blue color of flowers is {o perithable as to be of little ufe in dying. It is extraled from many by infu- fion in water, but not in fpirit. It is changed by acids to a red not more durable than the original blue ; by marine acid to the mott florid red ; and it is changed by alkalis and by lime-water to a green, which afterwards becomes a yellow. The green by lime-water is the more permanent and beautiful, and has been formed into lakes for painting. The two principal vegetable fubflances” ufed for dying of a blue color are indigo and #07, Thefe BLUE BLUE (PRUSSIAN). Pruffian blue is a precipitate of iron with a fuperabundant quantity of phlogifton, from: which it receives a very beautiful color. T This blue, which is fuccefsfully ufed in painting, was difcovered, like moft other things, by accident, and about the beginning of this century. Stahl relates in his Three hundred Experiments, N© 231, the manner in which this blue was difcovered. He fays, that a manufacturer of colors, called Diefbach, who ufually prepared a lake of cochineal, by mixing a decoction of this fubftance with alum and fome’ green vitriol, and by preci- pitating the mixture with a fixed alkali, being one day in want of fixed alkali, borrowed from Dippel, in whofe laboratory he worked, fome falt of tartar from which that chemift had feveral times diftilled his animal oil, and obferved that the lake precipitated by means of this alkali, inftead of being red, was of a fine blue color. Dippel, to whom he related the appearance, knew that it muft have been caufed by his alkali, and attempted to produce the fame effects by giving the fame quality to fixed alkali by an eafier procefs. His attempts fucceeded, and from that time Pruffian blue has been made. An account of this blue, called Pruffian or Berlin blue, from the place where it was made, was publifthed in the Berlin Memoirs for 1710, but no defcription was given of the procefs for making it. : Several chemifts undoubtedly attempted to difcover it - accordingly it was difcovered, and in the year 1724 Dr. Woodward publifhed it in the Philofophical Tranfa&ions. The procefs fucceeds very well, and is as follows : Alkalife together four ounces of nitre and as much tartar. See ALKALI (ExTEMPORANEOUS). Mix this alkali well with four ounces of dried bullocks blood, and put the whole in a crucible covered with a lid in which. there is a fmall hole : calcine with a moderate fire till the blood be reduced Thefe are fecule or fediments depofited by fermentation from infufions of the leaves of the plants azil, and woad, or glafium. Hellot thinks, that a fimilar blue dye might be obtained from _ moft other vegetables, and that the green of vegetables is caufed by a mixture of blue and yellow coloring particles, of which the blue is the moft durable, and leaft affected by fermentations. The colors given by both indigo and woad are at firft green, but are foon changed, by expofureto air, to blue. A blue tincture may be made from nepbritic wood, which has not been applied to any ufe. The cfeutial oils of camomile, milfeil, pimpinella nigra, are blue, and by keeping become green and yellow. See D¥ina. to BL UE t0 a perfect coal ; that is; till it emits no 3 more {i flame capable of blackening any white bodies Sy poled to i : increafe He fire towards the end, fo that the whole matter contained in th i but Emily os in the crucible thall be moderately, hrow into two pints of water the ma i tter i the crucible, while Jet red, and give it half a jog : decant this firf water, and pour more water upon thie oc] any coal till it becomes almoft infipid: mix ther a ele wate ili shou ho rs, and reduce them by boiling to lfo diffolve two ounces of martial vitri i ; : 1 vitriol, and eigh Pusices of alum in two pints of boiling water : Ary chia Sor : on when het, with the preceding lixivium, alfo hot : great effervefcence will then be made. The liquors will e fendered turbid, and will become of a green color more & efs blue, and a precipitate will be formed of the fame el or. F iltrate, In order to feparate this precipitate, upon ¥ ich pour fpirit of falt, and mix them well together y which means the precipitate will become of a fine blue x or. , It is neceflary to add rather too much fpirit of falt than too little, and till it no longer encreafes the beauty of the precipitate. The next day wath ‘this blue till the water comes off from -it infipid, and then ent] i Such is the procefs by which Pruffian So 5 Te Cheonily, after having difcovered it, endeavoured to find ’ e theory of it, and to explain the appearances in the everal operations of the procefs. - There have been feveral opinions concerning the nature of Pruffian blue. : Mr. John Brown of the Royal Society of London thinks that this blue is the bituminous or phlogiftic part of iron, difengaged by the lixivium of bullock’s blood, and applied ® the earth of alum. This opinion has been adopted by r. Geoffroy in the Memoirs given by him on this fubje&t which are found: in the collection “of the Academy of Sciences for the year 1725. y The Abbé Menon, a correfpondent of. the Academy of ciences, in Memoirs printed amongit: the collection of the Sgavans Efirangers, publifhed by the academy, advances and endeavours to prove that Pruffian blue is nothing but iro entirely freed from all faline matter by the phlogiffon of the alkaline lixivium, and precipitated with its natural color which, he pretends, is blue, He thinks that the ufe of the alum is to diminifh the int 76h oF Its cop e intenfity of the color by the white- 3 Lattly, B LU E Laftly, Mr. Macquer, having examined this matter in all its extent, has publithed a memoir amongft thofe of the Academy of Sciences for the year 1752, in which he con- cludes, after having related many experiments, that Pruf= fian blue is nothing but iron impregnated with a fuper- abundant quantity of phlogifton, which it receives from the phlogifticated alkaline precipitant. The experiments and difcoveries made by this chemift are as follow. Mr. Macquer firft obferves that very pure alkaline falts feparate iron, as they do all metallic fubftances, from acids; and that iron fo precipitated has a color more or lefs yellow, and is foluble by acids. If, on the contrary, this precipitation of iron be made by an alkali previoufly calcined with an inflammable matter, then a precipitate is formed, more or lefs green or blue, as the alkali was more or lefs phlogifticated. : If an acid be poured upon this green precipitate, experi- ments thew that this acid diflolves one part of it, and does not act upon the other. This proves that the green pre- cipitate is not homogeneous, but a mixture of two precipi= tates, one of which is foluble, and ‘the other is infoluble by'an acid. As the precipitate which refifts the action of acids is very blue, when feparated from that which the acid has diffolved, and as the green color of the mixéd precipitate is a mixture of yellow and blue ; the author concludes that the part dif- folved by the acid is yellow, and confequently that this portion of green precipitate is entirely fimilar to the iron which pure alkalis feparate from acids. As to the blue precipitate, as it not only refifts the ac- tion of acids but alfo of magnets, it might not be known to be iron, if a flight calcination did not at once deprive it of its blue ‘color, and render it entirely fimilar to other iron. Thefe falls prove that Prufian blue is nothing but iron united with fome matter which gives it a blue color, and the property of refifting the action of acids and of magnets. Mr. Macquer has further difcovered, that fire is not the only means by which the Pruffian blue may be deprived of all the properties, by which it differs from ordinary iron. A very pure alkali produces alfo the fame effect. He has alfo difcovered, that the alkali which has thus deprived the Pruffian blue of all the properties which diftinguifh it from ordinary iron, becomes by that operation entirely fimilar to the phlogifticated alkali ufed for the preparation of Pruflian blue. ; Thefe BL UTE _ Thefe fas feem to demonftrate that Pruffian blue is nos thing elfe than iron, which becomes blue by being impreg- nated with a matter which the alkali is capable of giving to it or of feparating from it, according to circumftances ; that is to fay, that when the alkali is impregnated with this matter, and is applied to iron diflolved in an acid, it then combines with this acid, and precipitates the iron, to which it transfers at the fame time the matter which changes the iron into Pruffian blue. But if on the contrary Pruflian blue be applied to pure alkali, then this alkali entirely dif- folves the coloring matter of the Pruffian blue, and takes it from the iron, which- is thus reduced to its ordinary con- dition. : - By a more particular examination of this alkali, im- pregnated with the coloring matter of Pruffian blue, either by calcination with an inflammable matter, or by taking the color from Pruflian blue itfelf, Mr. Macquer found that its alkaline properties were fo much more weakened, as it was impregnated with a larger portion of this coloring matter. This induced him to prefume, that by giving it a {ufficient quantity of Pruffian blue to difcolor, it might be entirely faturated with - this coloring matter : and the event entirely anfwered his expe@ation. By applying much Pruffian blue to an alkali, this latter was fo faturated that it no longer difcolored the blue when boiled together, and upon trial, was found to poflefs no longer any alkaline qualities. : A folution of iron by any acid poured into this alkali, faturated with the coloring matter of the Pruffian blue, forms immediately a precipitate, not green, compofed of _ yellow and blue, the former of which muft be feparated by an acid from the latter to obtain this of a pure blue color, as in the ordinary procefs for the preparation of Pruflian blue, but a fingle homogeneous precipitate, and a perfect Pruffian blue. his effect ought neceffarily to happen, be- caufe the faturated alkali contains no part purely alkaline which’ can occafion a precipitate of foluble iron, as pure alkalis do. But an eflential phenomenon, and not obferved by any former chemitt, is, that it 4s not merely by the action of the acid, which diffolves the iron, that the coloring matter is applied to the iron, and thus the Pruffian blue formed 3 but that the affinity of this matter to iron contributes alfo to produce this effe@®. The author has demontftrated this truth by the following decifive experiment. I BL UU & ure acid be poured upon an alkali perfectly fatu~ frei. wr the Selo -matter of Pruflian blue, this acid contradts no union with this alkali, nor is any-ways neu- tralized, and confequently is incapable of feparating the coloring matter of Pruffian blue. It only procures this feparation when it is united with iron, the affinity of which to the coloring matter, being joined to the affinity of the acid to the alkali, form a fum of affinities capable of occa- toning the feparation of which we treat. : Dn a, therefore, there is a very diftinét example of the effect of double or united affinities. See ArrFiNiTy. This example is even fo much more compleat, as it is amongft the moft general that chemiftry furnithes. For according to Mr. Macquer’s obfervations, iron is not the only metallic fubftance, the affinity of which being united with that of the acid, procures the feparation of the coloring matter of the Pruffian blue from the alkali; but any metallic fubftance diffolved in any acid feparates the phlogiftic matter from all alkalis, fixed or volatile. This |, is afcertained by Mr, Macquer’s experiments, a detail of which may be feen in his memoir. i Another no lefs important phenomenon, which none of the chemifts who have endeavoured to explain the theory of Pruffian blue had obferved, is, that earths have not the fame afinity as metallic fubftances with the phlogiftic matter of Pruffian blue. Hence if an alkali faturated with this coloring matter be poured into a folution of alum, no decompofition is effeted, nor is any precipitate formed. The alum continues alum, and the faturated alkali remains unchanged. After this experiment Mr, Macquer reafonably concludes, that the alum added in the operation of Pruffian blue does not directly contribute to the production of this blue. The purpofe to which it ferves is as follows. (e) : This chemift proved by many experiments, that an alkali can never be entirely faturated with the coloring matter of (¢) Alum is an ingredient in the above-mentioned receipt for making Pruffian blue firlk. publithed by Dr. Woodward ; but whether it be ufeful has not been afcertained by experiment. 1 have found that as good Pruffian blue may be made without as with alum; and that when this faline fubftance is ufed in the compofition, no good and intenfe blue can be obtained, till all the earth of alum, which had been precipitated, be again diffolved by the. marine or other mineral acid, all which are equally effectual. Vor. 1. N Pruffian BL UE Pruffian blue by calcination. This being eftablithed, it is certain that alkalis, calcined with inflammable fubftances to make the proper lixivium for Pruffian blue, fill remain alkaline. Hence it happens, that when they are mixed with a folution of green vitriol, they form by their purely alkaline part a yellow precipitate, fo much more copious as this purely alkaline part is itfelf more copious. But nothing is more capable of fpoiling the color of the portion cf iron precipitated in Pruffian blue than a mixture of this yellow -or olive-colored precipitate ; therefore a large quantity of acid muft be employed, that this yellow precipitate may be entirely diffolved, i we mean to have a very fine blue. Part of thefe inconveniencies is avoided by mixing a folu- tion of alum with a folution of green vitriol. By this means, the purely alkaline part of the lixivium is moftly employed to precipitate a greater or lefs quantity of the earth of alum, and confequently the quantity of yellow ferruginous precipitate is much diminifid, But the earth of alum being of a fine fhining white does not in the leaft alter the purity of the blue color, but enlivens it, and leflens its intenfity ; which is frequently no inconvenience, becaufe the Pruffian blue, when it is not of the fineft color, is always too dark and black. It follows from what has been faid, that when Pruffian blue is to be made with a lixivium not faturated, it is a matter of indifference whether the-green precipitate is to be again diffolved, or the alkaline part of the lixivium faturated with alum or with an acid, before the precipitate is formed. “The only difference which can proceed from thefe modes of management is, that in the former cafe, all the part of the precipitate which is not Pruflian blue is rediffolved by an acid ; whereas in the latter cafe, this mixed precipitation is prevented, and nothing is thrown down but true Pruffian blue. blue, that moft alkalis obtained from the afhes of vegetables, being combined by their combuftion with a portion of ‘inflammable. matter, are capable of furnithing a quantity of Pruffian blue proportionable to the quantity retained by them of this inflammable matter, even without the neceflity of mixing them with a folution of iron, becaufe they always contain a little of this metal diffolved, fome of which may be found in almoft all vegetables; therefore it is fufficient for this purpofe to faturate them with an acid. Thefe materials which form Pruflian blue in alkaline falts eccafion their It is proper to obferve, concerning the theory of Pruffian B.O NX # their impurity, and require much trouble to be perfeltly {eparated. | Some chemifts had even perceived the produ&ion of this blue in the faturation of alkaline falts, before the difcovery of the Pruffian blue: and Henkel particularly, who had obferved it in the faturation of the falt of foda, or foffil alkali, recommended to chemifts an enquiry concerning the nature of this blue. Thus chemifts had ‘already acquired fome fort of knowledge .on this fubject, and therefore the Pruffian blue could not have long remained unknown, even if accident had not prefented it in fo ftriking a manner to the chemift of Berlin, who was the firft who prepared it in fufficient quantity for the ufes of painters. : BLUE (SAXON). (f) | BOLE. Boles, or bolar earths, are clays which adhere to the tongue, when applied dry, and which are colored, yellow and red, by a ferruginous earth, See Cray. BOLOGNIAN STONE. See STONE. BONES. (g) (f) Biue (Saxon). The beft Saxon blue color may be given by the following compofition. ““ Mix one ounce of the beft powdered indigo with four ounces of oil of vitriol in a glafs body or matrafs; and digeft it for one hour with the heat of boiling water, fhaking the mixture at dif- ferent times ; then add twelve ounces of water to it, and ftir the whole well, and when grown cold filter it. ‘This produces a very rich deep color ; if a paler blue be required, it may be obtained by the addition of more water. The heat of boilin g water is fufficient for this operation, and can never {poil the color ; whereas a fand heat which is commonly ufed is often found to damage the color. *¢ Indigo which has been digetted with a large quantity of fpirit of wine and then dried, will produce a finer color than the former, if treated in the fame manner with oil of vitriol.” F xperi- ments to fbew the nature of Aurum Mofaicum, by Mr. Peter Wolfe. Phil. Tranf. 61. ’ Co (g) Bones are totally foluble in concentrated acids of vitriol, nitre, and fea-falt, and may be fofiened by thefe acids diluted, or by vinegar. From two ounces of ox-bone Neuman obtained by diftillation two drams of empyreumatic phlegm, one dram of volatile urinous {pirit, two fcruples of volatile alkali, two fcruples of fetid oil, and one ounce, three drams, and two fcruples of refiduum. Dr. Lewis obferves, that bones expofed to a heat gradually raifed are rendered white, opake, and friable; and when expofed fuddenly to a violent heat, are rendered hard, femi- tranfparent, and fonorous. Bones and horns may be ftained by the, common dying infufions and decoftions of vegetable and animal fubftances, and by metallic folutions. J N 2 BORAX SE —————————— ——— A —— Pr ————— B OR A X BORAX. Borax is a faline matter, with all the pro- . perties of a neutral falt. It is foluble in water, and cryftallizable nearly as alums is ; with this difference only, that it requires a fittle more water for its folution, and retains fomewhat lefs in its cry- ftallization. When.expofed to fire, it at firft undergoes the liquefa&ion occafioned by the water of its cryftallization, and is then calcined, as alum is, but is not fo much {welled and rarefied during the operation. ; If the fire be increafed to 2 melting heat, the borax is pretty eafily fufed, and is converted into a vitreous mattery or faline glafs: and when it is mixed with earths of any kind, it ais as a flux, and converts them into more or lefs tranfparent glafles according to their natuses. See ViTrI- FICATION. Glafs of borax is very friable, eafily tarnifhes in the air, and becomes mealy, nearly as the alkaline bafis of fea-falt does. It is entirely foluble in water; and when the folution of it is evaporated, borax is again formed in cryftals, as it was before its fufion. ; Borax then fuffers no decompofition by fire, even in open veflels, and certainly, therefore, not in clofe ones. But it may be decompofed by the vitriolic, nitrous, and marine acids, which unite with the faline alkaline master which is its bafis, and form with it exactly the fame neutral falts as thofe which refult from the union of thefe acids with the marine alkali; that is to fay, the vitriolic acid forms Glauber’s falt, the nitrous acid forms cubic nitrey and the marine acid forms fea-falt. When acids combine thus with the alkaline bafis of borax, they feparate from it a faline fubftance of a fingular nature, and little underftood, called Sedative Salt. See Sart (Se- DATIVE). We are far from knowing as much concerning borax as is defirable. We are even ignorant of its origin, which might fupply the want of a perfect analyfis, and give light to the nature of this faline fubftance. As borax is not found in Europe, it is brought from the Eaft-Indies in a ftate which only requires a flight purifica- tion, which is given to it by the Dutch and Venetians who are the’ chief merchants of it.” But it is not yet known whether this matter be a natural or an astificial fubftance, nor whence, nor how it is obtained. Our BO R"A'X Our ignorance concerning borax is certainly owing to the intereft, which they, who make a lucrative commerce of it, have to keep every thing concerning its origin fecret, However that be, notwithftanding the refources which chemifts poflefs of difcovering by their experiments what is hid from them, it appears that they were long in a ftate of indifference concerning borax. daished with employing it in their operations, in which it is very ufeful as a flux, they long ufed it without attempting to fubjet it to pro- per proofs for the difcovery of its nature, In the writings of Becher and Stahl we fcarcely find any thing concerning borax. The examination by chemical means of this fubftance, which ought to excite the curio- fity of chemifts, has been begun only in thefe later times ; and it is to the praife of the French, that almoft all the knowledge we have concerning it we owe to them alone. Homberg was amongft the firft who undertook a fet of experiments on borax, by which the fedative falt was dif- covered, which was a new fubftance, and entirely unknown before him. Homberg obtained the fedatiye falt from borax, by diftilling it with vitriol ; and imagining that he difco- vered a fedatjve or quieting power in it, he called it the - Narcotic Salt of Vitriol, or Sedative Salt. This chemift did not well underftand the theory of his experiment ; but that is not furprifing in matters fo new. The younger Lemeri, who after Homberg made many experiments on borax, difcovered that fedative falt may be obtained from it, not only by the vitriolic acid, but alfo by the nitrous and marine acids,. This difcovery was the more important, as it naturally led to further: but he feems to have been prevented by other purfuits from continuing this fubject as it ought to be, omberg and Lemeri obtained fedative falt only by diftil- lation or fublimation, which, particularly in this cafe, was a long and embarraffing operation. M. Geoffroy has im- proved upon their difcoveries, by fhewing the method of obtaining the fame falt from borax by acids with evapora- tion and cryftallization only, in greater quantity and with lefs trouble. We are alfo obliged to him for having firft demontftrated that borax contains the bafis of fea-falt. This truth he has firmly eftablifhed, by obtaining a true Glau- ber’s falt by mixing vitriolic acid with a folution of borax. Laftly, Mr. Baron, Member of the Academy of Sciences, and of the Faculty of Medicine at Paris, proved by many experiments that fedative falt of borax may he obtained by means B O.R AX means of vegetable acids, which had not been done before “him. He has alfo proved, that fedative falt is not a com- bination of an alkaline matter with the acid employed to obtain it, but that it exifts ready formed in borax, of which it is a principal or conftituent part; that the acids em- . ployed to extract it do only difengage it from the alkali with which it is united ; that this alkali is entirely fimilar to that of fea-falt; that fedative falt may be re-united with its alkali, and again form borax ; which is a complete proof that borax is nothing elfe than a compound of fedative falt, and marine alkali. Nothing more then remains to have, on the nature of borax, all the knowledge we can defire, than to difcover what this fedative falt is. The experiment by which Mr. Baron found that this falt is capable of decompofing nitre and marine falt, by ieparating the acids of thefe falts by help of fire, feems to fhew that vitriolic acid is one of the principles of the fedative falt, But to prove this decifively, the feative falt itfelf muft be decompofed. This is the fubje& of Mr, Bourdelin’s late admirable experiments. Al- though this able chemift has not been able to accomplifth his purpofe by all the methods which the moft profound chemiftry can fuggeft, his experiments are neverthelefs ufe- ful, as they may prevent others from employing their time and labor in making them, and alfo becaufe they make us better acquainted with the properties of the fedative falt. See SALT (SEDATIVE). (bh) BRAINS. - (hb) Borax, when crude, as itis brought from the Eaft-Indies, is called Zincal. In this fate, it confifts of fmall, yellow, gluti- “nous cryftals. It is faid to be refined by lime water. Refined borax confifts of large, white, eight-fided cryftals, each of which “1s compofed of fmall, foft, bitterifh fcales. It is difficultly fo- #luble in water, to which it gives a glutinous quality, and hence -1s ufed by dyers to give a glofs to filks. It is alfo foluble in “Apirit of wine, to the flame of which it gives a green color. By repeatedly moiftening it, while it is confrderably heated, it may be entirely fublimed. Borax renders all earths and ftones fufible by fire, and hence is ufed for the eflaying of ores. It alfo faci- litates the fufion of metals ; and is particularly ufeful when fmall particles of metal mixed with dirt and afhes are to be melted to- gether 3 as it promotes the fufion of the metal, and the vitrifica- , tion of the other matters, by which the particles of metal may difengage themfelves, and colle® into one mafs. It is further ‘ufefulin the fufion of metals, as it defends their furfaces fom the B RASS BRAINS. (i) BRANDY. (%) BRASS. Brafs, called alfo Latten, is a mixture of very pure copper, with a fourth part of very pure zinc, by which’ the color of the copper is rendered of a fine golden “yellow. This is undoubtedly the moft ufeful and neceflary of all the mixtures of copper and other metals, chiefly on account of the copper’s preferving fo much of its ductility, when com- bined with that proportion of zinc. Although zinc be only a femi-metal, and confequently not duétile, and although metallic mixtures be general- ly lefs ductile than the pure metals of which they are compofed, zinc feems to be an exception to this rule in its the combined ation of air and fire, by which imperfe&t metals are calcined. ~Crucibles in which gold and filver are melted ought to be previoufly glazed on their inner furfaces with borax, that when the metals are poured out, no particles may adhere to the fides of the crucibles. Gold is rendered pale by fufion with- borax, which effet is prevented by adding a little nitre or fal- ammoniac, or is remedied by remelting the gold with either of thefe falts. Dr. Lewis obferves, that borax alfo renders brafs and Prince’s-metal pale, and at the fame time acquires a deep red color. This color it probably receives from fome part of the copper contained in thefe compound metals, as it acquires the fame red color by fufion with copper. Borax is not, as fome fur pofe, a fubftance capable of reducing or reviving calcined metals, but is ufed with the intentions above defcribed. A principal ufe of borax is to facilitate the foldering of metals, which it does by accelerating the fufion of the furfaces of the metals to be joined, and by-clearing them from any calx or other matter by which they might be prevented from being perfectly applied to gach other, Borax is alfo ufed for the preparation of fome fine glafles, and imitations of precious ftones; becaufe the glafles prepared by fufing it with earths are hard, compa, bright, and very trani- parent ; but by long expofure to air they lofe much of their luftre, become cloudy, and when the quantity employed has been large, even opake. (7) Brains. From 16 oz. of ox’s brains, Neuman obtained by diftillation fix ounces, two drams, and two fcruples of a colorlefs phlegm ; four ounces and four {cruples of a volatile, empyreumatic {pirit ; which being reiified, produced two fcru- Ples of a volatile concrete falt, and one ounce of caput mortuum, from which, by elixation, were procured 25 grains of fixed falt. (#) Brawpy is an ardent fpirit diftilled from wine. For its roperties, fee SpiriT. Itis {aid to be imitated by adding tg ‘very pure malt fpirits fome dulcified fpirit of nitre. N 4 coinbinaticn BRASS combination with copper ; for it has the property of unit- ing with that metal in a large proportion, as of a third, or a fourth, without fenfibly diminithing the ductility of the copper. But as this property is quite peculiar to zinc, it is evident that it is neceflary, in order to make good brafs, that the copper and zinc be, each of them, in their greateft purty. If fuch zinc as is procured in the {melting of ores be melted with copper, as in fome mixtures commonly ufed, we might indeed obtain a very fine-colored brafs, but it would be brittle and unmalleable. It would only be a mix- ture of that kind called tombacs, becaufe this zinc is never very pure. See Zinc. This inconvenience is avoided in making brafs, by a kind of cementation with the ore of zinc, which is lapis calaminaris. This procefs is performed in the following manner. i A cement, compofed of one part and a half of good lapis calaminaris and powder of charcoal triturated together, and moiftened with water, is put into an earthen pot or cruci- ble. Then one part of very pure copper beat into plates, is placed over the cement, and the whole is covered with charcoal duft. The crucible is then clofed, and is heated only enough to make jt gradually become red. When the flame of the coals has acquired “a cupreous color, an iron rod is introduced into the crucible, to try if the copper be melted under the cementing powder. If that be the cafe, the altion of the fire is moderated, and in a few minutes the crucible is taken out. When it is cooled, the copper is found to have become yellow, and to have received an augmentation of a fourth, znd fometimes of a third of its weight, and is neverthelefs very malleable, ‘This procefs is a kind of cementation, in which the zinc is raifed from its ore in vapors, and combines with the copper. This method is advantageous, principally becaufe the other metallic matters, and particularly the iron, from. which lapis calaminaris is feldom free, do not rife in vapors, and confequently cannot combine with the copper. iy In order to effect this purpofe more certainly, the cement- ing powder may be mixed up with clay into a pafte; which being put in the bottom of the crucible, is to be covered with plates of copper and charcoal powder, proceeding as is directed aboye, The, copper, penetrated by the vapors of 3.7 the B R.A §85 the zinc which pafs through the pafte, melts upon the. furface of the pafte, and does not mix with the other metals, which always alters the color and duélility of the brafs. Thefe procefles are from M. Cramer. The advantages of converting copper into brafs are, that its weight is augmented one fourth part; that its color is wR to one more agreeable, as it approaches the cuior of ‘gold ; that it is more fufible; and laftly, that it is lefs fubject to ruft, becaufe zinc is lefs fufceptible than copper of being altered by the action of air and of water. * Although zinc be fixed to a certain degree in brafs by the adhefion it contra&ls with the copper, yet when brafs is melted and expofed to a violent fire during a certain time, the zinc diflipates in vapors, and’even flames away, if the heat be ftrong enough ; and if the heat lafts long enough, all the zinc will be evaporated and deftroyed, and the copper alone will remain. Copper, or copper converted into brafs, or in any other form, but particularly when penetrated by any falts and reduced into verdigrife, produces always, when taken in- ternally, the moft troublefome confequences, and becomes a poifon. For this reafon it is dangerous to ufe copper uten- fils and veflels for the purpofe of cookery, and in many places they begin to be difufed. = . ? or the fame reafon alfo, none of the preparations of this metal are ever employed medicinally by prudent phyficians: It appears, however, to enter into the compofition of a remedy much ufed, the Lilly of Paracelfus, or Tinéture of Metals : but in fat, it is certain that the f{pirit of wine, employed for the preparation of this medicine, diffolves pothing of the calx of copper, or of the other calxes of metallic fubftances digefted in it. Mr. Beaumé convinced himfelf of this fact by a moft accurate examination of the Lilly of Paracelfus. 3 The beft remedies for perfons poifoned by verdigrife, are mild, watery, mucilaginous, and oily drinks, given quickly and copioufly, which ought to be immediately fucceeded by evacuants to carry oft the poifon as faft as is poffible. The ufe of copper then in medicine is confined to exter- nal applications. It is ftimulant, tonic, and deterfive, Verdigrife enters into the unguentum Egyptiacum, into feveral plafters, the collyrium of Lanfranc, and the grecn palfam of Metz. - A blue water for the eyes is as . WH EA ——————————————————————— BR AS: 8 with copper and ‘fal ammoniac, which is called Celeflial water. ,.(1) BREAD. (!) Brass. As the manufafture of brafs is important in com- merce, a detail of the procefs by which it is made may be ac- ceptable. The calamine is previoufly to be prepared by cleanfing it from adhering earth, ftone or other matters ; by roafting or calcining it ; and by grinding it into a fine powder. The calci- nation, Bi which moifture and {mall portions of fulphur and other volatile matters are diffipated, may be performed either in a re- verberatory furnace, in which the calamine is kept till it be thoroughly red hot; and that this heat may be more equally given to it all at the fame time, it ought to be frequently ftir. red ; or by fetting fire to a conical pile, compofed of horizontal layers of calamine, and of charcoal placed alternately one upon the other, and of a lower firatum confifting of large pieces of wood ; in which lower ftratum are four horizontal channels, through which the air maintaining the fire paffes to the center, and thence arifes through a chimney or perpendicular empty {pace, left for that purpofe, along the axis of the conical pile. If the calcining heat be too intenfe or too long continued, part of the contained zinc may be diffipated ; and if it be not fuffi- ciently intenfe, or long enough continued, the volatile matters will not be entirely expelled, and the texture of the flone will not be fufficiently broken to prepare it for the fubfequent grind- ing. ‘The length of time and degree of heat requifite for the calcination of calamine, are different according to the qualities of that mineral. The calamine thus cleanfed, calcined, and ground, is to be mixed with about a third or fourth part of pow- der of charcoal, or of pit-coal, as is done in fome parts of Eng- land. The malleability of the brafs is diminifhed by the ufe of pit-coal, which is therefore employed only for the preparation of coarfer kinds of brafs. To this compofition of calamine and coal fome manufa&turers add common falt, by which the procefs of making brafs is {aid to be haftened. In Goflar, where the cadmia adhering to the inner fides of furnaces is employed, inflead of native calamine, a fmall quantity of alum is added, by which they pretend the color of the brafs is heightened. With this com. pofition, and with thin plates or grains of copper, the crucibles are to be nearly filled. The proportion of calamine to the copper varies according to the richnefs of the former, but is generally as three to two. The copper muft be difperfed through the com- pofition of calamine and coal, and the whole muft be covered with more coal till the crucibles are full. The crucibles thus filled are to be placed in a furnace funk in the ground, the form of which furnace is that of the fruftom of a hollow cone. At the bottom of the furnace, or greater bafis of the fruftum, is a circular grate, or iron place, This plate is covered with a coat of clay and Retain to fia ) defend BREAD - BREAD. The grains of all vegetables are almoft entirely compofed of {ubftances very proper for the nourifh- ment defend it from the ation of the fire, and pierced with holes, through which the air maintaining the fire paffes. The crucibles “ftand upon the circular plate, forming a circular row with one in the middle, The fuel is placed betwixt the crucibles, and is thrown into the furnace at the upper part of it, or the leffer bafis of the fruftum. To this upper part or mouth of the furnace is fitted a cover made of bricks or clay, kept together by bars of iron, and pierced with holes. This cover ferves as a regifter. When the heat is to be encreafed, the cover is to be partly or entirely taken off, and a free draught is permitted to the external air, which pafles along a vault under ground to the ath-hole, through the holes in the circular grate or plate, betwixt the crucibles, and through the upper mouth along with the fmoke and flame into an area where the workmen ftand, which is covered with a large dome or chimney through which the fmoke and air afcend. When the heat is to be diminifhed, the mouth of the furnace is to be clofed with the lid, through the holes of which the air, {moke, and flame pafs. The crucibles are to be kept red-hot during eight or ten hours, and in fome places much longer, even feveral days, according to the quality of the calamine ; during which time the zinc rifes in vapor from the calamine, unites with the copper, and renders that metal fufible by confiderably lefs heat than it is alone. To render the metal very fluid, that it may flow into one uniform mafs at the bottom, the fire is to be encreafed a little before the crucibles are taken out for the pour- ing of the fluid metal into moulds. From fixty pounds of good calamine and forty pounds of copper, fixty pounds of brafs may by this procefs be obtained, notwithftanding that a confiderable quantity of zinc is burnt and diffipated during the operation ; as we may learn from the blue flame round the mouths of the cruci- bles and furnaces, from the flowers of zinc which adhere to the ner fides of the furnace, and from the blue color communicated to the crucibles. The quantity of brafs obtained has been con- fiderably augmented fince the introdu@ion of the method now commonly pratifed of ufing granulated copper, by which a larger furface of this metal is expofed to the vapor of the zinc, and con- fequently lefs of that vapor efcapes. For the granulation of the copper, a cylindrical wooden refervoir is made, four or five feet .deep, in which a circular brafs or copper bottom may be raifed or lowered, by means of a chain. The refervoir is covered with a copper lid, in the middle of which is a hole half a foot in diame- ter, intended to receive an iron ladle pierced with holes, and coated with clay. The refervoir being filled with water, the melt- ed copper is poured through the holes in the lad'e into the water ; where it is broken by its fall inte fmaller drops or grains, is ren- | dered + B READ ment of animals; and amongft grains thofe which contain a -farinaccous matter are the moft agreeable and moft nutritive. Man, who appears to be defigned by nature to eat of all fubftances which are capable of nourifhing him, and fill more of vegetables than animals, has, from time immemo- rial, ‘and in all parts of the earth, ufed farinaceous grains as the principal bafis of his food: but as thefe grains cannot be without difficulty eaten by men in their natural ftate, this active and intelligent animal has gradually found means not only to extract the farinaceous ‘part, that is, the only nutritive part of thefe grains, but alfo to prepare it fo that it becomes a very agreeable and wholefome aliment, fuch as the bread we now generally eat. Nothing appears fo eafy at firft fight as to grind corn, to make a pafte with the flour and water, and to bake this pafte in an_oven. They who are accuftomed to enjoy the advantages of the fineff human inventions, without re- flecting on the labor it has coft to compleat them, think all thefe operations common and trivial. However, it ap- pears very certain, that. for a long time men no otherwife prepared their corn than by boiling and forming compa, vifcous cakes, not very agreeable to the tafte, and of diffi- cult digeftion, before they were able to make bread of good tafte and quality, as we have now. It was neceflary to invent and compleat ingenious machines for grinding corn, and feparating the pure flour with little trouble and labor ; and that inquiries, or rather fome happy chance, which fome obferving perfon availed himfelf of, thould difcover that flour mixed with a cerfain quantity of water is fufceptible of a fermentation, which almoft entirely deftroys its vifci- dity, heightens jts tafte, and renders it proper to make a dered folid by the cold water, and is colleted in the moveable bottom, which is afterwards to be raifed by the annexed chain, that the granulated copper may be taken out.——The above is the procefs generally employed for making brafs. Bat to make the finer and more malleable kinds of brafs, befides the choice of pure calamine and pure copper, fome manufafturers cement the brafs a fecond time with calamine and charcoal, and fometimes add to it old brafs, by which the new is faid to be meliorated. Brafs is brittle when hot, but is fo ductile when cold that it may be drawn into very fine wire. Its beautiful color, its hardnefs, its malleability, its fufibility, by which it may be eafily caft into moulds, and its quality of being lefs fubjeét to rut or verdigrife than copper, reader it fit for the fabrication of many utenfils. : li ght 2 BREAD light bread, very agreeable to the tafte, and of eafly digef~ tion. : ; This effential operation, on which the good quality of bread depends, is entirely of the province of chemiftry. It would add to the honour of the ancient cultivators of che- miftry, to attribute to them fo ufeful and important a difcovery ; but unhappily it is too probable that they had no fhare in it. ‘The ancient chemifts were engaged ‘in other purfuits than that of bread and other common objeéls. ‘They hoped to make gold; and what is bread in comparifon with gold ? : : : However that be, to the fortunate invention of raifing the pafte before baking we owe the perfection of the art of making bread. This operation confifts in keeping {ome pafte or dough, till by a peculiar fpirituous fermentation it fwells, rarefies, and acquires a fmell and tafte quick, pungent, fpirituous, fomewhat four, and rather difagreeable. A {mall quantity of this fermented dough is well worked with fome freth dough, which is by that mixture, and mode- rate heat, difpofed to a fimilar, but lefs advanced fermen- tation than that above-mentioned. By this fertnentation the dough is attenuated and-divided, air is introduced into it, which being incapable of difengaging itfelf from the tenacious and folid pafte, forms in it fmall cavities, raifes and fwells it: hence the fmall quantity of fermented pafte which difpofes the reft to ferment, is called lawven, from the French word lever, fignifying to raife. When the dough is thus raifed, it is in a proper flate to be put into the oven, where, while it is baked, it dilates itfelf ftill more by the rarefaGion of the air, and of the fpirituous fubftance it contains, and it forms a bread full of eyes or cavities, confequently light, and entirely dif- ferent from the heavy, compat, vifcous, and indigefted mafles made by baking unfermented dough. The invention of beer, or wine of grains, furnifthes a new matter ufeful in the making of bread. This matter is the froth which forms upon the furface of thefe liquors during fermentation. When it is mixed with dough, it raifes it better and more quickly than ordinary leaven. It is called yeaft or barm. By means of this the fineft, lighteft bread is made. It often happens that bread made with leaven dough has 2 fourith and not agreeable tafte, which may proceed from too great a quantity of leaven, or from leaven in which the fermentation has advanced too far. This inconvenience does not happen to bread made with yeaft ; I ~ becaufe BiR:O:N: ZI ¥E becaufe the fermentation of this fubftance is not too far advanced, or becaufe more attention is given to that finer bread. It may be afked, why, fince dough is capable of ferment- ing fpontaneoufly and fingly, as we fee from the leaven, a fubftance is added to difpofe it to ferment. The true reafon is, that all the parts of a fermenting fubftance do not ferment at the fame time, nor to the fame degree ; fo that fome parts of this fubftance have finithed their fermentation while others have not yet begun. The fermentable liquors which eontain much fugar, as hydromel, and muft of wines, give proofs of this truth; for, after thefe liquors have become very vinous, they have fill very diftinctly a faccharine tafte : but ajl faccharine matter is fl] fufceptible of fermentation ; and, in fa&, if vinous hydromel, or mufl, or even new beer, be diftilled, fo that all their ardent fpirit {hall be feparated, and the refiduums diluted with water, we fhall fee a fecond fermentation take place, and a Rew quantity of ardent fpirit formed. The fame thing precifely happens to dough, and fill more fenfibly, from its vifcofity and want of fluidity ; fo that if it be left to ferment alone, and without the help of leaven, as the fermentation procee ceflively, the parts which ferment four and vapid before all the reft b and changed, by which the bread able tafte. A mixture of a fmall quantity of leaven with dough effeCtually prevents this inconvenience ; becaufe the effect of this leaven, and of all fermenting fubftances, is to difpofe to a fimilar fermentation al] matters capable of it, with which it is mixed 3 or rather, by means of leaven, the fer- mentation of all the parts of fuch fubftances is effected more nearly at the fame time. Bread well raifed and baked differs from unfermented ‘bread, not only in being lefs compa&, lighter, and of a more agreeable tafte, but alfo in being more eafily mif- cible with water, with which it does not form a vifcous mafs ; and this circumftance is of great importance in di- . getflion. : BRONZE. Bronze isa compound of copper and tin, to which fometimes other metallic fubftances, particularly zinc, are added. Bronze BRONZE i . It is employed is brittle, hard, and fonorous : fc ik as for making bells, cannons, and Rotaes * ae proportions of the component metals are varie fuit the feveral ufes to which it is applied. ee Care The compound eof copper and tin has a grea ? Ee intermediate f{pecific gravity. - Two gunces oF ¢! Penal compofed of four-fifths of pure copper, and or thy of ure tin have feven grains and the tenth of 2a grain sof Bese gravity, than the fame quantities 9 wiv metals not allayed have. (m) ‘This proves: 3, union of copper and tin there is 2 penetration o past Js is, that one metal enters into He pores of the other. his effet is reciprocal. haps Ey and particularly Glauber sd Becker, have a long time ago remarked, that the f{peci greitis of metallic allays differed more or lefs From, wa Fe ought to be, if chere were no penetration, 3 Sighioies times the effect is contrary. But lately ¥ io 5 ater he been treated with more piseition, Sorel hi > fuch as Eifporn, Hahn, Krafft, an tort, dive given ts on this fubject. fults of well conduéted experimen Gellert’ Metallurgic Chemiftry. See the words ALLAY, GRA c) ; Mr LX A of the Royal Academy of Selencss, obferves, in his Memoir concerning the dutility % i 5 that when the mixture of copper with tin H Bale Las proportions ghove-sientiancd, Senn wi | : ns i lled and covered by tha ’ wii, of copper be four times the A ost, This fingular effect cannot be underftood without a i ing a total change in the fize and difpofition of the pore ab he compound metal ; which Sonfenuenuy ; a new p e reci I penetration of the two metals. ; . ody Tebo {fenfible to the action of falts, 9 moles, and of the air, than copper, it is allo en Tables iis bs £23 ) : : . z hence bronze is lefs apt to be covere » verge ing is. This is one reafon why thi yi De ftatues, and works expofed to the BE and weather. (m) The author means, I fuppofe, that a metiflie met, weighing two ounces, compofed of four fifths of OPP: 125d ane ffi part of tin, weighs, in water, 7,% grains be they she fame quantites of thefe two metals would together weigh, if not allayed, The ~ BUT TER BUTTE XR The greater fufibility of bronze than of copper is alfe ; aan fis an lime ors Pd, and much facilitates the cafting with a weak heat, and none of its principles are difengaged of large works, as ftatues, bells, and cannon. by the heat of boiling water. Thefe properties, together Laftly, a phenomenon worthy of attention is, that tin, with hae of not inflaming but with a heat greater than that though greatly fofter and lefs fonorous than copper, never- of boiling water, capable of decompofing it, and reducing thelefs renders this metal, by being allayed with it in a proper 1t to vapors, prove that the oily part of butter is of the nature of the mild, fat, and fixed oils obtained from many ion, more hard and more fonorous : hence this alla Proportion bells. : i y vegetable fubftances by expreflion. See Oirs (SWEET The operation by which large works of bronze are caft EXPRESSED). Is fufficiently fimple. For this purpofe a brick furnace is The half fluid confiftence of butter, as of moft other ufed, nearly the fthape of an oven for baking bread. The concrete oily matters, is caufed by a confiderable quantity floor of this furnace is concave, and confifts of a com- of acid, united with the oily part : but this acid is fo well pofition of fand and clay. In this hollow floor the metals combined, that it is not fenfible while the butter is frefh, and has undergone no change ; but when it grows old, and to'be fufed are put. The furnace has three openings. ; : The firft is a lateral mouth, at which enters the flame of undergoes fome kind of fermentation, then the acid is dif- wood placed in a fecond furnace on one fide of the firft; engaged more and more ; and this is the caufe that butter, like oils of the fame kind, becomes rancid by age. the fecond opening is a chimney placed on the fide oppofite g oilsol j 1 : to the mouth, by means of which the flame is drawn over he acid of butter is more quickly and fenfibly See the metal. The third opening is a hole which is opened by fire. If butter be expofed to a degece of fire rong and fhut at pleafure, through which the inner part of the enough to make it fmoke, vapors are exhaled from it in. furnace may be occafionally infpeéed, that the ftate of the fupportably acrid, which draws tears from the eyes, and metal may be obferved. When the metal is in the ftate Txcle coughing, as may be daily obferved in kitchens. required, a fourth opening is then unclofed, communi- eke vapors are nothing elfe than the difengaged acid. cating with the hollow floor, and through which the melted a he remaining part of the butter after this oper ation has a metal flows by channels into the moulds prepared to re- rong tafte, very different from its former mildnefs ; becaufe ceive ic. the part of the acid which is not exhaled is become fenfible BUTTER. Butter is the fat, oily, and inflammable and half-difengaged by the ation of the fire. The fame part of milk. This kind of oil is naturally diftributed j thing precifely happens when butter 1s diftilled in a retort. through 2ll the fubftances of the milk, in very {mall par- ro decompofe butter by diftillation, a much greater heat ticles, which are interpofed betwixt the cafeous and ferous than that of boiling water muft be applied to it: acid vapors parts, amongft which it is fufpended by a flight adhefion, 21s then raifed of confiderable volatility and acrimony. Thefe vapors are accompanied with a fmall portion of oil, but without being diflolved. It is in the fame ftate in | hich bot danie J which oil is, in emulfions; hence the fame whitenefs of which being that part which is moftly deprived of its acid, does not congeal ; then a fecond oil of a red color paffes, milk and emulfions, and hence by reft the oily parts fepa- hich rate from both thefe liquors to the furface, and form a wi Ich congeals when cold, and which becomes more and more thick as the diftillation advances. Laftly, a fmall cream. See EMuLsioN. : adv: quantity of charry matter remains in the retort, which in When butter is in the ftate of cream, its proper oily parts En £ D are not yet fufliciently united together to form a homogene- a re can be f{carcely burnt entirely, and reduced to ous mafs. They are ftill half feparated by the interpofition pov % U3 mais i P y po If the congealed oil in the receiver be again diftilled, of a pretty large quantity of cafeous and ferous particles. - ed ¢ pregty Age 4 y P more acid and fluid oil are obtained. Thus the whole of it The butter is compleatly formed by prefling: out thefe ed. heterogeneous parts by a of Ei percuffion. It Tey he reduced into acid and fluid oil by repeated diftilla« then becomes an uniform foft mafs. Frefh butter, which has undergone no change, has fearcely any fmell ; its tafte is mild and agrecable, it melts ; with The acid obtained is accompanied wi icy- panied with phlegm, particu larly at firft, and with a portion of oil united with i which t renders foluble in water, and to which it partly owes its oL. I. 0: 2 volatility. BOT TER volatility. It is owing to this oil that the acid has the eni- pyreumatic fmell of burnt butter, . There are many eflential remarks to be made upon this analyfis of butter by diftillation ; becaufe it prefents exactly the fame phenomena as the analyfis of all other concrete oily matters of the fame kind, fuch as wax, fuet, cacao butter, fperma-ceti, and may be confidered as a {pecimen of the decompofition of all thefe matters. Firft, it is neceffary that thefe diftillations fhould be made flowly, and with the precife degree of heat neceflary for continuing a moderate diftillation ; becaufe when the diftil- lation is too much hurried, the acid has not time to fepa- rate itfelf, and the concrete oily matter pafles almoft entirely into the receiver without fuffering any decompofition : but whatever management be employed, a confiderable part of this half-decompofed matter always pafles, which muft be fubjeted to future diftillations in order to reduce it to fluid oil. _ Secondly, when the diftillation is too much hurried, the acid paffes in white fenfible vapors from the quantity of oil united with it. For the fame reafon, towards the end of the diftillation, when the fire muft be raifed, the acid always paffes in this form of white fenfible vapors. Thirdly, at each diftillation of butter, or of its congealed oil, there is always a portion of oil entirely decompofed ; and thus the quantity continually diminifhes, and fenfibly. This quantity of entirely decompofed oil is proportion- able to the quantities of phlegm, acid, charry refiduum, or earthy phlogifticated matter, which are obtained at each diftillation, and are the proximate principles of the oil. "This remark is applicable to the diftillation of any oil. - See Or. We ought alfo to obferve in general upon this analyfis of butter, that this matter, although derived from animal - bodies, does not yield a particle of volatile alkali; neither does the fat of animals; which proves that thefe fubftances . are not affimilated to other animal fubftances, all which, when decompofed, furnifh volatile alkali, without except- ing the oils obtained from thefe fubftances. Butter is conftantly ufed in food, from its agreeable tafte ; but to be wholefome, it muft be very frefh, and free from rancidity, and alfo not fried or burnt; otherwife its acrid and even cauftic acid being ‘difengaged, diforders digeftion, renders it difficult and painful, excites acrid, empyreu- matic belchings, and laftly, introduces much acrimony into BUTTER into the blood. Some perfons have fo delicate ftomachs; that they are even affected with thefe inconveniences by frefh butter and by milk. See MiLk. This obfervation is alfo applicable to oil, to fat; to chocolate; and in general to all oleaginous matters. BUTTER of ANTIMONY. Butter of antimony; called by fome chemifts the glacial sil of antimony, is com- pofed of marine acid united with the réguline part of anti- mony: ; : This is one of the tombinations which cannot be made directly ; that is, by the application of pure and liquid marine acid to the regulus of antimony ; for in this manner the marine acid, however ftrong; diflolves none, or almoft' none, of the regulus: but when the acid is in its higheft degree of concentration, reduced almoft to drynefs, as it is in feveral combinations, and when the body to which it is united has a weaker affinity to it than the regulus of anti= mony has, then it quits that body to unite with the regulus, and forms the butter of antimony: - Marine acid united with mercury has all the above-men- tioned conditions; wherefore butter ‘of antimony may be made by mixing together corrofive fublimate and regulus of antimony, both well powdered, and by applying a certain heat and diftillation. | : Lemeri, the moft exa& of the operators who have written, fays, that the beft proportion of corrofive fublimate and regulus of antimony is fixteen parts of the former to fix parts of the latter. He obferves, that this mixture fre- quently becomes very hot, fome time after it has been made. his heat proceeds from the re-action of the two matters upon each other even without fire. To proceed to the diftillation of butter of antimony : this Mixture muft be put in a retort of convenient fize, the neck of which ought to be large and fhort; this retort is to be placed in a furnace with a fand-bath ; a receiver is to be luted, and the diftillation is to be carried on at firft by a gentle fire, which is to be encreafed as more heat becomes neceflary to continue the operation ; a heavy liquor rifes, Which congeals in the receiver when it cools ; this is the butter of antimony. The operation is ftopped when it appears that it cannot be continued without a great encreafe of heat, by which fluid mercury would be diftilled inftead of butter of antimony. If then it be required to obtain this mercury, which is a Very pure mercury, revived from corrofive fublimate, bafore O 2 the BUT HTER the fire is encreafed, it is proper to remove the receiver, and apply another containing fome water. It is evident, that as the marine acid only unites with. the regulus of antimony by difengaging itfelf from the mercury of the corrofive fublimate, this latter metal ought to appear in its proper fluid form ; but as it is lefs volatile than the butter of antimony, it does not rife till this has pafled, and the fire be encreafed. Butter of antimony may alfo be made by ufing antimony itfelf inftead of its regulus; becaufe the acid of corrofive fublimate attacks as eafily the regulus of antimony in the antimony itfelf, although it be there united with fulphur, as when it is pure: but it is evident, that in this cafe more antimony muft be ufed, than the requifite quantity of regulus in the preceding operation, Lemeri obferves, that twelve parts of antimony are neceffary for fixteen parts of corrofive fublimate. When butter of antimony is made by this latter method, it more readily congeals, and is more folid than when made with the regulus. ‘ Mr. Baron, in his notes on Lemeri’s Chemiftry, fays, that this proceeds from the greater quantity of acid con- tained in the butter made with the regulus than in that made with antimony. This matter would require a parti- cular examination. , However that may be, a part of this butter made with antimony always congeals in the neck of the retort, and is frequently accumulated there in fufficient quantity to block up the paflage, by which means the confined vapors may occafion an explofion. This inconvenience is prevented by applying a hot-coal near the neck of the retort, by which the butter is melted, and made to flow into the receiver. It is evident, that when the butter of ‘antimony is made with antimony, if the diftillation be continued after the butter has pafled, we fhall not then obtain fluid mercury, but a combination of mercury with the fulphur of the anti- - mony, that is, a cinnabar will be fublimed. This is called the cinnabar of antimony. See MERCURY, SULPHUR, and CINNABAR. ! This cinnabar makes its appearance towards the end of the operation by red vapors. As foon as thefe are feen, the receiver ought to be changed. The butter of antimony made by either of thefe opera- tions, efpecially by the latter, is generally rendered mesg oF e BUTTER lefs impure by fome fluid mercury, or by fome cinnabar, which are raifed along with it: but it is eafily purified from thefe extraneous fubftances by a fecond diftillation with a entle heat, when it paflfes very white and pure. This Sond diftillation, as all other repeated diftillations and fublimations for the purifying of fubftances, is called refi- cation. Sweet fublimate, mercurial panacea, and white precipitate, are alfo mercurial combinations with marine acid ; and, like the corrofive fublimate, are capable of being decompofed by means of regulus of antimony, and of forming with it kinds of butter of antimony. “But Lemeri obferves, that thefe butters are lefs cauftic than that made with corrofive fublimate ; undoubtedly, becaufe thefe mercurial compounds contain lefs marine acid. Laftly, butter of antimony may be made with luna cornea, which 1s 2 combination of filver with very concentrated marine acid, which is nearly in the fame flate as it is in corrofive fublimate, (fee Luna CorNEA); becaufe the marine acid has lefs afhnity with filver than with regulus of antimony. This butter is called the lunar butter of anti- ony. Butter of antimony then contains a very concentrated marine acid, which is not fo intimately engaged with the regulus of antimony as to lofe all its properties ; hence we may account for the property which the butter of antimony has of attrating moifture from air, and for its caufticity ; for it is ftrongly corrofive, and is applied, like lapis infer- nalis, to ulcers and to carious bones. Sez CAUSTICITY. This metallie falt has been called butter, from its con- fiftence, which is nearly the fame as that of butter, and orm the facility with which it melts with a very gentle eat. Butter of antimony ought to be clafled amongft the falts which are at once “cryftallizable and deliquefcent ; for however confufed the mafs feems after diftillation, it is in fal a heap of very fmall cryftals. By the operation of butter of antimony, and its pro- perties, feveral effential properties of the marine acid and of regulus of antimony are difcovered. ; Firft, although the marine acid has a great affinity with this femi-metal, it cannot diffolve it, but when highly concentrated. ‘This phenomenon is analogous to thofe prefented by the marine acid with mercury and with filver, to both which it has a great affinity, but which jt cannot 3 diolve BUTTER diffolve unlefs it be very highly concentrated, or applied to them when their aggregation is broken ; as we fee by the Qperations of making white precipitate, corrofive fublimate, luna ¢ornea, and of the concentrated parting. See al, thefe words. Secondly, the property which the hutter of antimony has “of not being decompofed by fire alone, as the metallic falts are which contain the vitriolic and nitrous acids, depends on the great adhefion which the marine acid contracts with the regulus of antimony, as it generally does with other metallic matters, and on its property of volatilizing them, or carrying them aleng with it in diftillation; which we fee happens in corrofive fublimate, luna cornea, fmoking fpirit of Libavius, and many other chemical operations, in which the moft fixed metals are carried off by marine acid. ‘Thirdly, the butter of antimony is by the affufion of water changed in its nature, or rather is divided into twa parts, one of which is perfectly diffolved by the water, and another part is precipitated, being infoluble by water. The diffolved part contains its greateft poflible quantity of acid, and the precipitated part contains the leaft poffible quantity of acid. This latter part, when well wafhed, is called mercurius vite, or powder of algaroth. See PowDER of AL- GAROTH. Mr. Beaumé pretends, that the powder of algaroth is improperly faid to contain the leaft poffible quantity of acid, fince, by a fufficient lavation, he has been able to deprive it of every veftige of an acid. Butter of antimony is foluble in nitrous acid; and this {olution is made with great yiolence : afterwards, by eva- ‘poration of the acids, a white calx of antimony is formed, called Bezoar mineral, See that word. BUTTER ¢f ARSENIC. Butter of arfenic, called allo corrofive oil of arfeni¢c, is a combination of marine acid with arfenic. This combination is made by a procefs {imjlar to that of the butter of antimony. According to semeri, equal parts of butter of arfenic and corrofive fublimate ought to be pulverifed, well mixed, and diftilled together ; by which a butyraceous liquor is obtained fimilar to butter of antimony in its external appearance. ~ When the diftillation cannot be continued without con- fiderably encreafing the fire, the receiver ought to be taken, off, and another receiver, in which there is fome water, adapted to the retort; then, upon raifing the fire, fluid mercury may be obtained. See BuTTER of ANTONE is BUTTER This experiment fhews that the asinlsy of marine acid to arfenic is greater than to mercury. In this operation the mercury is revived from the corrofive {ublimate. + It is evident that this butter of arfenic muft be a moft violent cauftic. It ought not to be ever ufed, from its poifonous quality. 8ee ARSENIC. : , It does not appear that this combination of marine acid with arfenic has beeen carefully examined by any chemift. BUTTER of CACAO. Butter of cacao is an oily, concrete, white matter, of 4 firmer confiftence than butter, or even than fuet. This fubftance is extrated from the kernel of a fruit called cacao, with which chocolate is made. As the butter of cacao is a true congealed oil, it cannot be obtained without a heat fufficient to melt it. ‘The beft method is to bruife the cacao, and to boil it in water. Almoft all the fuperabundant and uncombined oil, which this fubftance contains, is liquified, and feparated from the parenchyma and extractive part; and as it is lighter, it fwims on the furface of the liquor in which it is left to congeal, that it may more eafily be taken off. This butter is generally mixed with fome broken folid bits of the cacao fruit, from which it may be purified by melting with a very gentle heat without water, in a pretty deep veflel, and by keeping it thus melted, long enough for an entire fepara- tion of the matters to take place according to their {pecific gravities. By this method, a very white and pure butter of cacao may be obtained. ; This oily concrete fubftance has a very mild tafte; it has no aromatic fmell; it does not rife in diftillation without 2 heat fuperior to that of boiling water ; by diftillation it is partly decompofed ; laftly, it does not flame, till it is fuffi- ciently heated to be reduced into vapors. As thefe are precifely the properties of mild and fat oils obtained from ee and animal matters by expreffion only, the butter of cacao muft be undoubtedly ranged in this clafs ; and as it is concrete, it is analogous to other concrete oily matters of the fame nature, fuch as wax, fat, butter of milk, &c. It alfo prefents the fame phenomena as thefe fubftances do, when decompofed and attenuated by diftillation ; for which reafon, fz¢ BUTTER. il Butter of cacao has quite the fame medicinal properties as all the mild exprefled oils. It is emollient and blunting when not rancid; it enters into the compofition of poma- tums, See O1Ls (SWEET EXPRESSED). 0 4 BUTTER CA DMIA BUTTER of WAX. Butter of wax is nothing but half-decompofed wax ; that is, wax deprived of a part of its acid by diftillation. As this acid is the caufe of the con. fiftence of the oily part of wax, the reafon is evident why the butter is fofier than the wax itfelf, It has a ftrong fmell, and, when left expofed to the air, it does not refume its confiftence, in which it effentially differs from refinous matters, Sze Wax. - oe > of TIN. Butter of tin is a name given by a combination of tin with the concentrated marine acid of corrofive fublimate. a re Tin, as well as the regulus of antimony, has a ftronger affinity to marine acid than mercury has. If therefore corrolive {ublimate and tin, reduced to {mall parts, be mixed together, thefe two fubftances will ad upon each other even without the application of Heat, fo that in time the mixture _ becomes moift, and attrads the humidity of the air. If thefe fubftances be diftilled together immediately after their mixture, the corrofive fublimate js much more quickly decompofed by the tin 5 the marine acid quits the mercury to unite with the tin, the greateft part of which it carries off along with it. In this diftillation a kind of marine Jalt with bafis of tin pafles over. Part of this combination is in form of a liquor which fmokes continually, even when cold. This is called the Smoking [pirit of Libavius. Another part is raifed .in a concrete form, which more particularly deferves the appellation of utter of tiny although it feems that feveral chemifts give this name indifferently to the liquor or concrete matter, or to both of them at the fame time. See Spirit (SMOKING) ¢ Lisavius. BUTTON. By the word button, is meant the meta] which is collected generally in a roundith mafs at the bottom of a crucible after fufion, or which remains in the cupels after cupellation. HI {2D MIA. The name of Cadmia, or Calamine, is iven to feveral different fubftances.” What js called the Cadmia of the furnaces is a matter which is fublimed when ores containing zinc, like thofe of Rammelfberg, are {melted. This cadmia confifts of the flowers of zinc fublimed during the fufion, and adhering to the inner furfaces of the walls of furnaces, where they fuffer a femi-fufion, and therefore acquire fome folidity. = So great a quantity of thefe are fois te | colleéted, CALCINATION collefted, that they form very thick incruftations, which mutt be frequently taken off, The name of Cadmis of fur- naces, has alfo been given to all the foots and metallic fublimates formed by {melting in the great, Sitheugh there certainly are great differences in thefe matters. See MELT~ ING of os api ; ~ Several authors call Native or Foffil Cadima, a fort of fone or mineral; containing zinc, iron, and fometimes other {ubftances. It is of a yellow or reddith color, and isalfo called Calamy, Calamine, or lapis calaminaris. Beth this mineral and the Cadmia of Furnaces are ufed for the preparation of brafs. See Brass. ~ Laftly, fome chemifts have given the name of Foffil Cadmia to a mineral containing arfenic, frequently bifmuth, filver, and particularly the femi-metal, the calx of which being melted with vitrifiable matters, forms a beautiful blue ~ glafs. This mineral is better known by the name Cobalt, which alone ought to be given to it, to avoid the confufion attending the application of the fame name to different fubftances. S§e CopaLr. : - CALAMINE. Se Cabmia, and OREs of Zinc. CALCINATION. The calcination of a body is, properly fpeaking, the expofing of it to the ation of fire, to produce fome change upon it. ‘The principal effets of fire in chemical operations are to carry off the volatile principles, and to feparate them from the fixed, or to occafion the combuftion of inflammable matters. ~Herice it follows that bodies are calcined either to deprive them of fome volatile principle, or to deftroy their inflammable principle, and fometimes for both vj thefe purpofes, pt We have examples of the firft kind of calcination, in ex- pofing calcareous earths and ftones to the fire, to convert them into quicklime, which is effected by the entire eva- poration of the watery principle contained in this kind of €arth, See Quick LIME. The calcination of Gypfum, of Alum, of Borax, and of feveral other Salts, by fire, which deprives them of the water neceflary for their cryftallization ; the roafting of minerals, by which the fire carries off the fulphur, arfenic, and other volatile contents 3 ought to be referred to the firft - kind of calcination. : e have an example of the fecond kind of calcination, by expofing imperfect metals to fire ; by which they lofe their inflammable principle, their form, ‘and metallic pro- ‘ '; perties, CALCINATION perties, and are changed into earthy matters called Metallic Calxes, / It is neceflary to obferve, that this fecond calcination differs effentially from the firft, as the changes produced by it upon imperfe@ metals are not effected by evaporation, but by decompofition and deftrution of their phlogifton. It is therefore a combuftion, and not a wolatilifation of their inflammable principle. Hence it follows, that the firft kind of calcination ma fucceed without the conta of air and in clofe veflels, al- though it is more quick and complete in open veflels, from a property of air, by which it greatly accelerates the eva- poration of volatile bodies. See Air. But as the fecond kind of calcination is a true combuftion, like that of all inflammable bodies, - it requires all the conditions neceffary for combuftion, and particularly the free accefs of air. See ComBUSTION and CALXES (METALLIC). There are many bodies, in the calcination of which an evaporation of volatile parts happens, and alfo a deftruction or deprivation of their inflammable principle, although without any fenfible combuftion of this latter. Such par- ticularly are all combinations of imperfect metallic matters with vitriolic and nitrous acids: when thefe bodies are ex pofed to fire, their acid evaporates, and at the fame time carries off with it their inflammable principle. We have examples of this kind of calcination in expofing to fire Martial Vitriol and Bezoar Mineral, As vitriolic acid, and ftill more nitrous acid, deprive the imperfect metals of more or lefs of their phlogifton even without fire, feveral of thefe metals, particularly iron, .Copper, tin, regulus of antimony, are reduced, after they have been diffolved in thefe acids, toa ftate fimilar to that of calcination with accefs of air; that is to fay, they be-- come earths, not poflefled of metallic properties, which they cannot refume without the addition of _phlogifton. Hence moft chemifts confider acids as capable of calcining thefe metals, and they accordingly call earths of metals which have been dephlogifticated “by acids, without fire, Calxes. Laftly, nitrous acid, when engaged in a fixed alkali, that is, nitre having the property of inflaming when applied to a combuttible fubftance with a red heat, and of making the phlogifton of thefe bodies burn, becomes a very ‘powerful agent for the calcination of many fubftances; and ‘parth= cularly of imperfect metals and charry matters, ~ Sze Mire ‘“ e CA LX ES We have a very good example of this kind of calcination in the preparation of diaphoretic antimony. This calcination of metals by nitre is effected partly by a dephlogiftication fimilar to that by nitrous acid in humid folutions, and partly by combuftion : which does not hin- der it from fucceeding without accefs of air, and in clofe veflels, from the peculiar property of nitre in this refpe&. See NITRE. It is proper to obferve, that certain preparations of gold and filver are improperly called calxes, becaufe they are not truly calcined, no method being known by which they can be deprived of their phlogifton. Sez Gol, SILVER, and METALS (PERFECT). What is improperly called Calx of Gold, is nothing but gold reduced into very fine particles, either by amalgamation with mercury, or by its feparation from other folvents. Moft of thefe improper names, found in fuch numbers in chemiftry, proceed from the ignorance of ancient chemifts, and fill more of alchemifts, who all believed, for example, that they had procefles for decompofing and calcining gold. Nothing is more equivocal than the pretended calcinations of perfect metals. We cannot, however, affirm its impof- fibility. Some fats even feem to make it probable ; fuch as the deftruction of gold in the focus of Thirfnhaufen’s great lens, an account of which is publifhed by Homberg in the Memoirs of the Academy of Sciences, and the cal cination of gold by long reverberation, in the manner of Ifaacus Hollandus.” But if the moft fimple and eafy expe- riments of chemiftry require frequent repetition to be fuf- ficiently eftablifhed, certainly thefe, which are exceeding & difficult and laborious, require great attention. See OMBUSTION, for [ome effential obfervations regarding the fe- cond kind of calcinatian. CALXES of METALS. Metallic calxes are earths of metals deprived of their phlogifton, and confequently of their metallic properties. All metallic fubflances, excepting gold, filver, platina and mercury, are fufceptible of being deprived of their inflammable principle by feveral methods. The firft method is by burning their phlogifton in open air, and by a calcination, or rather a A fimilar to that of all other combuftible matters. See CALCINATION and COMBUSTION. The fecond method is by applying to metals acids capa- ble of depriving them of their phlogifton, fuch as vitriolic acid, ¢C AL XES acid, and particularly nitrous acid. This kind of calci- nation of metals is made in the humid way, and by folu- tion. 8ee SoLuTION. The third method is by nitre, with which metallic mat-" ters may be detonated. his third method, which is com- pofed of the two former, is the moft efficacious and expe- ditious. Sec NrTRE, and DETONATION of NITRE. The earths of metals deprived of phlogifton by any of thefe methods have properties peculiar to each, concern- ing which the articles of the feveral metallic fubftances ought to be confulted ; but they alfo have properties ge- neral and common to all. 'Thefe are the following: Not only calcined metals lofe the chara&eriftic proper- ties of metals, but alfo the following changes are effected. “The more perfectly metallic matters are calcined, the more they lofe of their fufibility ; fo that very fufible fubftances, Tuch as tin and regulus of antimony, are rendered by a per- fect calcination, (that is, till they become very white) bodies abfolutely infufible, and which ‘may be claffed amongft thofe that are refratory. Hence ‘it is proved that phlogifton is the principle of: fufibility of metals. In proportion as metallic fubftances lofe their phlogif- ton, they become more fixed. This property is lefs fen- fible in metals, from their fixity, than in femi-metals, all which are very volatile when in their metallic ftate, and the calxes or earths of which become exceedingly fixed, as we fee very evidently from the example of diaphoretic antimony, which refifts the moft violent fire without the leat lofs, and which recovers all its volatility, if it be re- ftored to its reguline ftate by addition of phlogifton. This proves ‘that phlogifton is a principle effentially volatile, and that it communicates its volatility to certain bodies with which it is combined. Metallic earths become lefs foluble in acids, and particu- larly in nitrous acid, by being deprived of phlogifton, as we may perceive from crocus martis when well calcined, from calxes of tin, of regulus of antimony, &c. Hence we are led to conclude, that the folubility of metallic fubftances by acids, and particularly by nitrous acid, depends on the - Intervention of phlogifton: for if calxes be reduced by adding phlogifton, the metals refulting from that reduction will then recover their {olubility. What we have faid concerning the general changes produced by calcination of metallic matters, upon their fufibility, their fixity, and folubility, may alfo be applied ¥ to 7 CAMPHOR to their opacity, their fpecific gravity, in a word, to all their metallic properties, which are always diminifhed fo much more in metallic calxes, as they are more perfectly dephlo- gifticated. “This feems to indicate, that if an entire and perfect calcination of metallic fubftances could be effeted, they would then have no metallic property, and perhaps they would not fpecifically differ from each other, and only be one and the fame kind of earth. This is certain, that when the calcination of metals has been too long continued, their calxes become irreducible, or at leaft much more difficultly reducible; and this reduction is always made with lofs, fo that the quantity of metal originally calcined is never again obtained. ; Although metallic calxes are effentially different from calx of ftone or quicklime, they have neverthelefs fome fimilar properties, particularly thofe which relate to fixed and volatile alkalis. Thus, for example, fixed alkalis re- ceive from metallic calxes the fame caufticity and properties as from quicklime; and volatile alkali may be feparated « from fal ammoniac by metallic calxes, and particularly by minium, 2s it may by quicklime; and it receives the fame changes, that is, 1t- becomes more penetrating, is always fluid, and cannot be reduced to a concrete ftate, when treated with a fufficient quantity of thefe matters. See QuicKLIME. CAMOMILE. (0) CAMPHOR. Camphor is a vegetable, concrete, very volatile fubftance, and igflammable, as effential oils are 3 of a ftrong fmell, and eafily foluble in {pirit of wine. From all thefe properties, camphor perfectly refembles reflins; but on theother fide, it eflentially differs from them in this, that when expofed to fire in clofe veflels, it is entirely fublimed without fuffering any decompofition, and without leaving any refiduum of coal or other matter. Although it has a {trong tafte, it has not the acrimony of effential oils : the moft cauttic alkalis do not at upon it: the vitrio- lic and nitrous acids diflolve it, but without effervefcence, (eo) CamomiLe. In the cup of the flowers of camomile refides a mall quantity of blue effential oil. The flowers contain alfo a faline fubftance, which being extraded by decoition in wine, precipitated filver and mercury from nitrous acid, and thefe pre- Cipitates were different from luna cornea and corrofive fublimate, euman.. Camomile flowers have been found by Dr. Pringie’s e¢xperiments to poffefs eminently an antifeptic quality, heat, CAMPHOR heat; inflammation, Acorching, or other fenfible change, even when thefe acids are concentrated. . Nitrous acid diffolves camphor without commotion ; and the folution is clear and limpid. It is called Qi/ of Camphor: hen it is mixed with too much water, the mixture becomes turbid and milky, becaufe the acid has a ftronger affinity with water than with camphor. ‘The camphor then quits the acid, and appears in white ‘flocks, which foon precipitate to the bottom of the containing veflel, their weight being encreafed by fome adhering acid. But when this acid is taken off by the water, the flocks of camphor rife to the furface, and there float. When they are com- pleatly wathed and dried, they are found to be comphor entirely fimilar to what it was before this folution and pre- cipitation, ‘This is a manifeft proof that campher receives no change from the nitrous acid ; which, however, of all acids, acts the moft powerfully upon oily matters. See O1Ls (EsseNTiAL) and REsins, Jor the refemblances and differences betwixt camphor and thefe fubfiances. It follows from what has been faid concerning the proper= ties of camphor, that this fingular fubftance, although it has many of the effential properties of oils and refins, is not, however, comparable to any of thofe which are known, and forms a clafs apart. As, excepting its concrete ftate, camphor approaches more to the nature of ether, precifely by thofe very properties in which it differs from oils, it is to be prefumed that this fubftance is analogous to ether, as Mr. Macquer conje@ures in hisgElements of ‘Chemiftry. See ETHER. NR All the camphor which is fold comes from India and Japan. It is procured from 2 kind of laurel called Laurus Camphorifera, great numbers of which grow in the ifland Borneo.” A long time this tree was believed to be the only vegetable containing camphor ; but feveral modern chemifts, and particularly Mr. Cartheufer, have difcovered, that many aromatic plants, as thyme, rofemary, fage, and almoft all the ,labiated kind, contain a fubffance of the ‘nature of camphor, which may be extracted, although in very {mall quantities. Cas when firft extralted from its tree is mixed with many impurities, and is then called Rough Comphor. The Dutch, who chiefly make a trade of it, purify it by fubli- mation in glafs matraffes. Camphor is ufed in medicines as fedative and antifpaf- modic. It fucceeds well in many convulfions, and other nervous CARDUUS nervous affections. This quality is common to it, and to all other ethereal, oily, volatile fubftances, fuch as Ether, Dippel’s Animal oil, highly rectified Efential Oils, Mufk, Caftor, Opium, and other fimilar fubftances. Hoffman has obferved and commended, more than any other phyfician, the fedative powers of camphor. This fubftance is alfo very + fuccefsfully ufed as a powerful antifeptic; and when dif- folved in {pirit of wine, is employed againft gangrenes. CANTHARIDES. (p) CAP. The piece which terminates the top of a melt- ing furnace is called the Cap. This piece has the form of an oblong dome. In one fide there is a large oval door, intended for the introduction of a confiderable quantity of coal at a time, becaufe this kind of furnace confumes a great deal, and muft be quickly fupplied. The upper part of the cap is terminated by a tube or chimney, which may be lengthened at pleafure by the addition of other tubes ad- jufted to each other. Sez FURNACE (MELTING). CAPITAL. The Capital or Head is the upper part of an alembic.. See ALEMBIC. CAPUT MORTUUM. This is a Latin name given to fixed and exhaufted refiduums remaining in ree torts after diftillations. As thefe refiduums are very different, according to the fubftances diftilled, and the degree of heat employed, they ought to be fpecified more particularly by adding a term denoting their qualities ; as, for example, we might fay, Larthy Refiduum, Charry Refiduum, Saline Refiduum, &ec. This method is more accurate and diftin&, and is chiefly uled by modern chemifts. CARDAMOM. (4) CARDUUS. (r) CARMINE (?) CantTHuARIDES. Thefe infe@s contain a very acrid refi- nous fubftance, fix drams and two feruples of which were extract- ed by fpirit of wine from four ounces of cantharides. The fi. mulating power of cantharides is caufed by this fubftance, and not, as fome imagine, by a volatile alkali, of which they yield lefs by analyfis than fome other animal fubftances, and none without the a&ion of fire. Neuman. (49) CarDaMoM. An ounce of the feeds of the leffer carda- mom contain about a fcruple of effential oil, by which their pungency and aromatic {fmell are caufed, with fourteen grains of refinous extra®t, and forty-five grains of mucilage. Neuman. (r) Carbpvuus BenepicTus. From four ounces of the leaves of this plant may be obtained about 4} drams of refinous i : . C“A"U §*T 1.¢C CARMINE. (5) CARNELIAN. (1) CASE-HARDENING. (u) CASSIA. (x CASTOR. (y ~~ CAUSTIC (COMMON). Cothmon cauftic is 4 fixed alkaline fal, fharpened b quicklime, and deprived of all moifture by drying and fufion. The alkali employed for this, preparation is generally potath, A lixivium is made with quicklime, like that of the foap-boilers, called foap-leys. See Lixivium of Soap-orLers. This lixi- vium is to be evaporated to drynefs in a copper or filver veflel. Afterwards the dry matter is to be put into a cru- cible, and expofed to fire till it flow like melted wax. . Then it is to be poured into a bafon, and quickly cut into . by means of fpirit of wine 3 or from the fame quantity of leaves, about 61 of mucilaginous extra& by means of water. In the juice of this plant, after proper depuration and evaporation, {a- line cryftals fimilar to tartar are formed. Neuman, (s) Carmine is a red pigment prepared by diffolving cochi- neal in an alkaline lixivium, and precipitating the folution by alum. It confifts, therefore, of the coloring matter of cochineal adhering to the earth of alum. (t) CarnerLian, Carneolus, or Sardus, is a {emi-tranfparent reddith agate. Sec Agate. (u) CasE-HARDENING Of iron is a fuperficial converfion of that metal into'fteel by the ordinary method of converfion, name- ly, by cementation with vegetable or animal coals. This opera- tion is generally pra@ifed upon fmall pieces of iron wrought into tools, and inftruments, to which a {uperficial converfion is fuf- ficient; and it may be performed conveniently by putting the pieces of iron to be cafe-hardened, together with the cement, in an iron box, which is to be clofely fhut and expofed to a red heat during fome hours. By this cementation, a certain thick- nefs from the furface of the iron will be converted into fteel, and a proper hardnefs may be afterwards given by fudden extin@ion of the heated pieces of converted iron in a cold fluid, See STEEL. : (*) Cassia. The fruit called Cafia Fiftularis contains a {weet {aline fubftance, foluble in water or in fpirit of wine. Neuman. (1) Castor, Two drams and a fcruple of extra may. be ob- tained from an ounce of caftor by fpirit of wine, or by water. By diftillation with water, the peculiar fmell of the caftor is given to the water: hence we may probably infer that it contains an effen- tial oil. By diftillation with fpirit of wine, none of this peculiar {mell is given to the fpirit, Neuman. 3 pieces . BAY 8 AO pieces, ‘while it is ftill hot and moift, and is to be fpeedily put into a glafs bottle, well clofed with a glafs ftopper, ~ An alkali thus treated is much more cauftic than ordinary fixed alkali. - It is alfo more fufible by fire ; and it attra&g the moifture of the air much more readily ; for which reafon it ought to be cut and put into bottles, while it is yet hot; otherwife it would become very foon moift. This alkali when applied to the {kin during half or threé quarters of an hour, corrodes it, and forms a painful efchar, like that produced by burning. It is employed to open iflues, which formerly were much ufed, bat were after wards almoft abolithed. They have fince been brought again into frequent ufe, and juftly ; for they are fervice- able by evacuating vicious fluids which refift other remedies. But at ‘prefent common cauftic is. not much ufed for the opening of iffues, becaufe it occafions a quick and long pain. . The common method at prefent is to make an in- cifion with a knife, and to promote the fuppuration by me- thods well known in fur ery. The cautticity of common cauftic muft not be believed to proceed from a perfe@ drying and concentration of the alkali. This concentration does indeed augment its caufti- city ; but we are no lefs certain, that independantly of that, alkalis treated with quick-lime are much more alive and cauftic, even when they are fluid, than any other al- kalis. This is evident from the effe&@s of the lixivium, or ley of foap-boilers, which almoft inftantaneoufly corrodes and deftroys all animal matters. This caufticity then is caufed by fome particular change produced upon alkalis fixed or volatile by quick-lime; which change probabl confifts in depriving them of fome unctuous matter, which invelops and ‘blunts their faline principle. See AtxarLl (Fixep), ALk arr (VoLATILE), AMMONIAC Sarr, Spirit (VoLaTiLE) of SAL AmMmonIac, Lixivium of Soap- BOILERS. CAUSTIC (LUNAR). Lunar cauftic, or Lapis Infernalis, is a cauftic made by taking from lunar cryftals all their water of cryftallization by fufion. To make the lunar cauftic, cryftals of filver are to be put into a Heflian crucible, which ought to be large in pro- portion to the quantity to be ufed, becaufe 2 confiderable {welling and frothing happens in the beginning of this fufion. he crucible is to be placed in a furnace which ought to draw little air, and furrounded by 2 very {mall quantity of lighted coals, becaufe thefe cryflals are very fufible, and oL. I, Pp too CAUSTIC td0 great "heat would be prejudicial to the preparation of the lunar cauftic. This matter is then to be very quick- ly liquefied. In the beginning particularly, the heat ought to be moderate, otherwife a part of the matter might flow over the crucible, and deflagrate like nitre upon the coals, by which the filver would be reduced. While the ebulli- tion gradually diminifhes, the fire is to be encreafed ; and when the matter is brought to a perfect and tranquil fufion, it is to be caft into an iron mould previoufly heated and grand in its inner furface. The lunar cauftic is there to e left till it is fixed and cold, and then it is to be put into | a bottle with a glafs ftopper. The lunar cauftic ought to | be formed into fmall cylindrical pieces, like pencils, of | about a line in diameter, and the furgeon who ufes them puts 4 them in a crayon or pencil cafe, to prevent his fingers being [8 injured by touching them. The mould for the lunar cauftic | is fo made as to give them that form. It confifts of five | or fix hollow cylinders, placed vertically and parallel to [% each other, to which a gutter is adapted, by means of which | the matter is poured into them. This mould is compofed | of two pieces which exactly fit each other, in each of | which the fame number of hollow femi-cylinders correfpond | to. thofe of the other. By this difpofition, when the lunar | cauttic is caft and cooled, it is obtained in entire cylinders, © by feparating the two pieces of the mould. The lunar cauftic muft be poured as {oon as it is in tran- quil fufion, for that degree of heat is fufficient to carry off its acid, which may be obferved to diffipate in fumes; | and confequently, if it was left in the fire long after it is | thus fufed, it would lofe fome of its caufticity, which it q entirely owes to this acid. The operation for lunar cauftic thews two remarkable | phenomena. The firft is the black color affumed by the | cryftals of filver thus fufed. I believe this color proceeds | from a part of the phlogifton of the nitrous acid, which | attaches itlelf to the filver fuperficially, and which al- | ways gives a black color to this and other white metals, | fuch as mercury, lead, and bifmuth, when it is thus united | to them. The other remarkable phenomenon is a certain fymme- | try of arrangement, or cryftallization, which lunar cauftic | takes when it cools and becomes folid. If a pencil of } tunar cauftic be broken into pieces, its inner fubftance may | be obferved to be compofed of needles or radii pafling from the circumference to the center, much like the infide of the © CAUSTICITY the round ferruginous fulphureous pyrites. This phenome- non is common to all bodies of a certain degree of fimpli= city of compofition, which pafs without agitation from a liquid to a folid ftate, and is a fpecies of cryftallization. Perhaps the fame phenomenon occurs in many other neutral - falts in which it has not yet been remarked. See Cry- STALLIZATION. Lunar cauftic ought to be made with tefted filver. If filver allayed with copper be ufed, the cryftals of filver ought to be well drained upon brown paper, by which they will be freed from the folution of copper, and will become: white. This folution of copper in nitrous acid when dried is alfo cauftic, but lefs fo than lunar cauflic. It alfo has the inconvenience of becoming moift in the air, See SILVER, CausticiTy, and CrysTALS of SILVER. - CAUSTICITY. By this word is denoted a quality belonging to feveral fubftances, by the acrimony of which the parts of living animals may be corroded, and deftroy- ed. Bodies which have this quality, when taken inter- nally are true poifons. The caufticity of fome of thefe, as of arfenic, is fo deadly, that even their external ufe is profcribed by prudent phyficizns, : Several others, as nitrous acid, lapis infernalis, or lunar caufiic, common cauflic, buiter of antimony, are daily and fuc- ceisfully ufed to confume excrefcences, to deftroy fungous fleth, to open iffues, &e. They fucceed very well when properly employed, and fkilfully managed. The caufticity of bodies depends entirely on the ftate of the faline, and chiefly of the acid matters which they con- tain. When thefe acids happen to be at the fame time much concentrated, and flightly attached to the matters with which they are combined, they are then capable of alting, and are corrofive and cauftic. Thus fixed and vo- latile alkalis, although they are themfelves cauftic, become much more fo by being treated with quick-lime, becaufe this fubftance deprives them of much fat or inflammable matter, which binds and reftrains the a&ion of their faline ~ Principle. (2) By this treatment then, the faline prin- ciple is more difengaged, and rendered more capable of action. Alfo, all combinations of metallic matters with acids, form falts more or lefs corrofive, becaufe thefe acids (xz) The fubftance which quick-lime takes from alkaline falts, by which the diffolving power of thefe falts is encreafed, is fixable arr See Gas. Pa are CEMENT are deprived of all their fuperabundant water, and are be- fides but.imperfeétly faturated by the metallic matters. Neverthelefs, fome other circumftance is neceflary to conftitute the caufticity of thefe faline metallic matters. For the fame quantity of marine acid, which when pure and diluted with a certain quantity of water fhould be in- capable of producing any harm, fhall however produce all the effects of a corrofive poifon when it is united with mercury in corrofive fublimate, although this fublimate fhall be diffolved in fo much water, that its caufticity cannot be attributed to the concentration of its acid. This effect is attributed by fome chemifts to the great weight of the metallic parts with which the acid is united. This opinion is very probable, fince the caufticity is no- thing but its diflglving power, or its difpofition to combine with other bodies ; and this difpofition is nothing elfe than attraction, which is one and the fame thing as weight or gravitation. CAWK. (a) CEMENT. Al thofe powders and paftes are called cements, with which any body is furrounded in pots or cru- cibles, and which are capable, by help of fire, of produc- ing changes upon that body. Hence the expreflions #0 cement, and cementation. The principal cements are the royal cement, which is ufed to feparate filver from gold in the operation called Concent rat- ed Parting ; (fee PARTING (CONCENTRATED) the cement for converting iron into fteel (fee STEEL) ; the cement for converting certain glafs into porcelain ( Jee GLASS and Por- CELAIN) ; the cement for converting copper into brafs. See BRASS. Cements may be made of many various kinds, and for various purpofes, by varying the materials of the compo- fitions. ~ Cementation is generally a very powerful method of producing changes upon bodies, or of forming combina- tions which could not otherwife be eafily effe@ted ; becaufe in this operation the active matters of the cement are in a (a) Cawk isawhite, very denfe, fparry fubftance, foluble in acids, and fufible by fire. It is generally found in or near lead mines. If an ounce or two ounces of cawk be thrown red-hot upon fixteen ounces of melted antimony, and the fufion continued about two minutes 3 a regulus weighing fifteen ounces will be obtained hard aud white, See Phil. Tranf. Num. 110. This experiment Dr. Lewis has frequently repeated with fuccefs. {tate C-E-R U-§ -§ ftate of drynefs, are reduced into vapors, and affifted by con- fiderable heat. CEMENT-COPPER. (3) CENTAURY. (¢) CERUSS, or WHITE LEAD. Cerufs is a kind of ruft of lead which has been corroded and half-dif- folved by vapors of vinegar. To make cerufs, leaden plates rolled {fpirally, fo that the fpace of an inch fhall be left betwixt each circumvolution, muft be placed vertically in earthen pots of a pratoe fize, containing fome good vine- gar. Thefe leaden rolls ought to be fo fupported in thé pots, that they do not touch the vinegar, but that the vapor of this acid may circulate freely betwixt the circums volutions : thefe pots are to be covered, and placed in a bed of dung, or in a fand-bath, by which a gentle heat may be applied. The acid of vinegar, which very well diffolves lead, being thus reduced into vapors, eafily attaches itfelf to the furface of thefe plates, penetrates them, and is im- pregnated with this metal, which it reduces to a beautiful white powder called Cerufs: when a fufficient quantity of it is collected on the furface of the plates, the rolls are taken out of the pots, and unfolded; the cerufs is then taken off, and they are again rolled up, that the operation may be repeated. This management is very ingenious; becaufe the plates of lead thus difpofed prefent the greateft furface to the vapors of vinegar, while they occupy the leaft poffible {pace, Pe in this operation the acid of vinegar is overcharged with lead, this metal thus changed into cerufs, is not pro- perly in a faline fate; hence cerufs is not in cryftals, nor is foluble in water: but a faline quality would render it unfit for painting, for which it is chiefly employed. Cerufs ground and prepared for painting is called white lead. It is the only white hitherto found fit for painting in oil. The difcovery of another white for this purpofe is defirable, not only from its faults as a paint, hut alfo from (4) Cement, or Ziment CoPPER, is copper precipitated from vitriolic waters by iron. The v.ame is derived, as is faid, from a vitriolic water in Hungary called ziment. (c¢) Centaury. The leaves of the lefler centaury contain a bitter fubftance foluble by water, or by {pirit of wine. The green color of the plant refides in the refinous part, being extracted by fpirit of wine, but not by water. Tw Pa | its i i i i 1 1] A { ig 8 { ha fy 4 | i i Ei ae i Bt § f RE § ti | A | Ey + Ee Hi i | 145 1 JA it ; B ! i $4 i . ! 8 ai Ee —— CEMENT are deprived of all their fuperabundant water, and are be- fides but imperfectly faturated by the metallic matters. Neverthelefs, fome other circumftance is neceflary to conftitute the caufticity of thefe faline metallic matters. For the fame quantity of marine acid, which when pure and diluted with a certain quantity of water fhould be in- capable of producing any harm, fhall however produce all the effects of a corrofive poifon when it is united with mercury in corrofive fublimate, although this fublimate fhall be diflolved in fo much water, that its caufticity cannot be attributed to the concentration of its acid. This effect is attributed by fome chemifts to the great weight of the metallic parts with which the acid is united. This opinion is very probable, fince the caufticity is no- thing but its diflglving power, or its difpofition to combine with other bodies ; and this difpofition is nothing elfe than attraction, which is one and the fame thing as weight or gravitation, CAWK. (a) CEMENT. AH thofe powders and paftes are called cements, with which any body is furrounded in pots or cru~. cibles, and which are capable, by help of fire, of produc- ing changes upon that body. Hence the ex preflions fo cement, and cementation. The principal cements are the royal cement, which is ufed to feparate filver from gold in the operation called Concentrat- ed Parting ; (fee PARTING (CoNCENTRATED) the cement for converting iron into fteel ( fee STEEL) ; the cement for converting certain glafs into porcelain ( fee GLASS and Por- €CELAIN); the cement for converting copper into brafs. See BR Ass. Cements may be made of many various kinds, and for various purpofes, by varying the materials of the Compo~ fitions. Cementation is generally a very powerful method of producing changes upon bodies, or of forming combina- tions which could not otherwife be eafily effected ; becaufe in this operation the alive matters of the cement are in a (a) Cawk isawhite, very denfe, fparry fubftance, foluble in acids, and fufible by fire. It is generally found in or near lead mines. If an cunce or two ounces of cawk be thrown red-hot upon fixteen ounces of melted antimony, and the fufion continued about two mingtes ; a regulus weighing fifteen ounces will be obtained hard and white, See Phil. Tranf. Num. 110. This experiment Dr. Lewis has frequently repeated with fuccefs. ftate CER U-8§ § ftate of drynefs, are reduced into vapors, and affifted by con- fiderable heat. CEMENT-COPPER. (3) CENTAURY. (¢) CERUSS, or WHITE LEAD. Cerufs is a kind of ruft of lead which has been corroded and half-dif- folved by vapors of vinegar. To make cerufs, leaden plates rolled fpirally, fo that the {pace of an inch thall be left betwixt each circumvolution, muft be placed vertically in earthen pots of a proper fize, containing fome good vine- gar. Thefe leaden rolls ought to be fo fupported in thé pots, that they do not touch the vinegar, but that the vapor of this acid may circulate freely betwixt the circum» volutions :" thefe pots are to be covered, and placed in a bed of dung, or in a fand-bath, by which a gentle heat may be applied. The acid of vinegar, which very well diffolves lead, being thus reduced into vapors, ecafily attaches itfelf to the furface of thefe plates, penetrates them, and is im- pregnated with this metal, which it reduces to a beautiful white powder called Cerufs : when a fufficient quantity of it is collected on the furface of the plates, the rolls” are taken out of the pots, and unfolded; the cerufs is then taken off, and they are again rolled up, that the operation may be repeated. This management is very ingenious ; becaufe the plates of lead thus difpofed prefent the greateft furface to the Vapors of vinegar, while they occupy the leaft poffible {pace, Pa in this operation the acid of vinegar is overcharged with lead, this metal thus changed into cerufs, is not pro- perly in a faline ftate; hence cerufs is not in cryftals, nor is foluble in water: but a faline quality would render it unfit for painting, for which it is chiefly employed. Cerufs ground and prepared for painting is called white lead. It is the only white hitherto found fit for painting in oil. The difcovery of another white for this purpofe is defirable, not only from its faults as a paint, hut alfo from (fb) CEMENT, or ZIMENT CorPER, is copper precipitated from vitriolic waters by iron. The name is derived, as is faid, from a vitriolic water in Hungary called ziment. (¢) Cgntaury. The leaves of the lefler centaury contain a bitter fubftance foluble by water, or by fpirit of wine. The green color of the plant refides in the refinous part, being extracted by fpirit of wine, but not by water. Ea | P 3 its Ae re J bt i tH i 4 ¥ J i vd ; } 1 | % i 1 f AR [i TH Yi | r 3 { § 3 i UA) 4 | if r 9 ES a i Hig ¥ ma 3 ! CHARACTERS its injuring the heglth of perfons employed in its manufac. ture, by affecting them with a fevere difeafe, which lead and all its preparations frequently occafion, called the coli; of “ -aminerals, or the colic of painters. Cerufs, like the other preparations of lead, is drying, fedative, and lenient; as fuch it is employed, but io externally. Itisan ingredient in many ointments, plaifters, and other pharmaceutical Preparations defigned for external maladies. As lead is much divided in cerufs, and is already pene- trated with a certain quantity of acid of vinegar, its fatura- tion with this acid may be eafily compleated, by diffoly- Ih geeruis in diftilled vinegar. Thus the lead is entirely re- duced to a faline ftate. From this faturation a cryftallizable neutral falt with metallic bafis refults, called fugar or Jalt of lead. Sc Sugar of Leap. CERUSS 7 ANTIMONY, This name is given by forme chemifts to a pearl-colored matter, or white earth, which feparates from the water with which diaphoretic antimony has been wathed. It is the fineft part of the white calx of antimony, which has been difiolved by the alkali of nitre formed in this operation. The peculiar earth of the alkali, fome of which always feparates after every calci- nation and folution, probably makes a part alfo of the cerufs of antimony. See DrapHoRETIC MiNERrAL. CHALK. Chalk is a calcareous earth, found in form of friable ftones, and therefore cannot be polithed as marble anc other hard calcareous ftones may. Chalk is alfo found in powder. This fubftance has ail the properties which eharaligrie calcareous earths. See EARTHS (CALcAREA ous), CHALK (BLACK). (4) CHARACTERS. Chemical chara&ers are figns in- vented to reprefent the principal fubftances and operations in “a concife manner. Thefe figns ought to be underftood, be- caufe they are ufed by many authors, and in tables of affini- ties. Seeihe annexed T ALE of CHEMICAL CHARACTERS. (2) C AALK (Brack); bums nigra pilloria 3 atramentum Seifile. 'T his is a light, earthy, flakey fubftance ufed for draw. 13g black lines on paper, and for mixing with oil or water for the ufe of painters. It is calcinable by fire to a reddith white earth. It is unfoluble by acids, and feems to be a bituminous flate. Wallerius fays, that in Sweden, near Huneberg, a black earth is found as difufible in water as Indian ink, CHEESE. CHEESE CHEESE. Cheefe is the mucilaginous or gelatinous part of milk. As the milk of all animals is a true emul- fion, the cheefe or eafeous part of milk is an intermediate fubftance by which the oily or butyraceous part of this liquor is divided, and fufpended in the ferous part. Thus cheefe is in milk what mucilage is in emulfions or milky juices of vegetables; but although it has fome properties common with mucilages, it differs in other refpeéts, parti- cularly in its want of duétility, or its vifcidity, and in its property of coagulating by heat and by acids. Milk is compofed of three very different fubftances, butter, cheefe, and whey, Thefe fubftances are only well mixed together, but not combined, fince they are capable of a fpontaneous feparation or analyfis: but this feparation is not entire and exact, except it be procured by methods peculiar to each of thefe fubftances. See Butter, MiLk, and WHEY. To have cheefe as pure as is poffible, freth milk, after the cream is well taken off, muft be curdled by runnet, or by cream of tartar; the whey then muft be well drained from it, and it muft be frequently wathed with much pure water. If it be then expofed to diftillation with a graduated heat, at firft a phlegm arifes which has a flight fmell of milk or of cheefe, without any marks of an acid or of an alkaline quality. This phlegm arifes with the heat of boiling water; and when the heat is encreafed an oily and faline fpirit arifes. The faline part of this fpirit is generally a volatile alkali. Afterwards a {mall quantity of empyrey= matic oil arifes, which is at firft fluid, and becomes more and more thick and fetid. Concrete volatile alkali. alfo arifes in this diftillation ; and at length when the retort is very red-hqt, and nothing more rifes, a confiderable quan- tity of coal remains. This coal is of that kind which cannot be burnt without very great difficulty. From this analyfis of cheefe, which refembles the analyfis of all animal matters, this fubftance appears to be the moft animalifed part of the milk; for butter and whey furnifh other principles, and particularly much acid. We mut, however, obferve, that cheefe made of the milk of frugivo- rous animals may furnifh acid, inftead of volatile alkali. This difference depends perhaps on the nature of the aliments ufed by the animals from which the milk is taken, and alfo of their temperaments, difpofitions, and nature of theis digeflions ; for, in general, the flate of the acid, and its Co 4 greats ) 1 i | ! 8 i 8 ¥ Mlk | y H Ib i an # 8 J IE I § b i . bi | a 1 i { aE | Wt gt | d 1 | CRE H it } 5 a. , 4 x Hi of ga 4 £ ) by 1 Ed 4 | i & - 3 "4 . : 4 3 i A ¥ i i ! | ] | i | i 3 gl Es Ee Ei b } 8 { : HE ¥ H i oe 4.1] ag i ; - 1 1 | 2 i i IRE $3 3 ART CINNABAR : ransformed into volatile y variable in the animal kingdom, particu- animals which live only on vegetables, and in Sey ch fill more approaches to a vegetable na- This matter, although very interefting, h It} as been h neglected by chemifts. We Tr in a of Prac- tical Chemiftry, heefe produced from cows milk, and in that analyfis no mention is made but of an acid, which fhews the variations that may happen in this matter. We with it were examined as accurately as jt but for this rent feafons of the year. ’ nas 32 Y. Chemiftey is a fcience, the object 1s to difcover t erti i : ads fof € properties of bodies by.analyfis The advantages refulting from this fcience are too mani- I n CHERT. (.) CHRYSOLITE. (f) CINNABAR. Cinnabar is \ of two kinds; one j native, the other is artificial. ’ ° (e) C HERT, or CHERTZ ; petrofilex Semipellucidus, lapis cop. news, bornflein of ‘the Germans,” Chert is a femi-tranfparent fone of the filiceous kind. See its chemical properties under the ar. ticle Earn (ViTririasre), It js generally lefs hard and of a coarfer texture, than common flints. Large quantities of chert are found in beds of lime-ftone, as flint fi . chalk, with this difference, tha ints ore found in the beds of grinding ftones for grinding calcined fli : ices, ut have too fmooth and clofe a texture for the grinding of (/) CHrYsoLiTE is a pellucid, yellowith green ftone or pe . . - 3 § mn, De fixth in hardnefs from diamonds, yet fufceptible of improfion From a file. By fire it fuffers no other change than lofs of color. t 1s probably a fpecies or variety of topaz. Its chemical proper- ties fee under l (Vitririasrs), This gem ding twenty grains of crocus martis to two and fix ounces of miniym, ‘ CINNABAR Native cinnabar is a heavy and brittle mineral, of a very deep red color when it is in a lump, and confifts of fhining, needle-like, parallel ftriz. This mineral is compofed of mercury and fulphur, as will be proved when we hall relate its analyfis. It is, pro- perly fpeaking, mercury mineralifed by fulphur, or a true ore of mercury. Cinnabar cannot be attacked in the humid way by any chemical agent. It is volatile; fo that, when expofed to fire in clofe veflels, it is entirely fublimed, without {uffering any decompofition. ‘The fublimation may be repeated any number of times without any change upon the fubftance. If cinnabar be expofed to the aétion of fire, with accefs of air, it is decompofed by the burning of its fulphur, and then the mercury difengages itfelf in vapors; but as thefe vapors are not eafily to be colleéted, and as many of them would be loft by this method of decompofition with accefs of air, another method is employed of decompolfing cinnabar in clofe veflels, by means of fome fubftance to which ful- phur has a greater affinity than to mercuiy. Many fub- ftances are known to be poflefled of the quality required for this purpofe. Fixed alkalis, quicklime, calcareous earths, iron, copper, tin, lead, filver, bifmuth, and regulus of antimony, have a greater affinity than mercury has to fulphur, and confe- quently are capable of decompofing cinnabar. Of thefe fubftances iron is found to be the moft convenient, and is therefore moft ufed for the decompofition of finall quantities of cinnabar. When this decompofition is to be made, equal parts of filings of iron and cinnabar are to be well mixed together, and put into a retort, which is to be expofed in a furnace to a naked fire, or in a fand-bath fo difpofed that a fufficiently firong heat may be applied ; a receiver containing water is to be adapted to the retort, and the diftillation to be promoted. The mercury difen- gaged from the fulphur by means of iron is railed into vapors, moft of which are condenfed in the receiver, at the bottom of which, under the water, they appear changed into fluid mercury; a fmall part of the mercury remains much divided, and floats on the furface of the water in form of a black powder, which muft be carefully collected, 2nd mixed with the mafs of fluid mercury, with which it eafily incorporates ; this mercury, which is then to be {trained through clofely woven linen, is very pure. It is called mercury revivified from cinnabar ; and this redu@ion is called revivification CINNABAR revivification of mercury from cinnabar. In the retort is found a mals compofed of the iron employed, and of the fulphur of the cinnabar; or if, inftead of iron, fome other fubftance was employed, it would be found after the operation united with the fulphur. Thus if an alkali or calcareous earth has been employed, an earthy or alkaline liver of fulphur will be found. “See SuLphur. By weighing the cinnabar employed in this procefs, and the mercury obtained by it, this mercury is found to be feven-eighths of the whole cinnabar, Thus in cinnabar feven parts of mercury are united with one part of ful phur, From a knowledge of the conflituent parts of cinnabar we may learn a method of compoling an artificial cinnabar entirely fimilar to the natural. For this purpofe, mercur and fulphur muft be fufed and triturated together till they unite well, and form a bjack body called Ethiops mineral, See Etniors MingraL. This Ethiops mineral i then to be fublimed ; but we muft obferve, that the operation is attended with fome difficulties; fo that a beautiful and perfeét cinnabar, in which the mercury and fulphur are exactly proportioned, cannot be obtained by the firft fubli- mation. ‘The firft fublimate is always overcharged with fulphur, which gives it a black color. The reafon of this 15, that more fulphur is neceflarily employed to make the ethiops mineral than is fufficient to form cinnabar: but pb each fubfequent fublimation fome of that fuperfluous ful- phur is feparated, till at length, by five or fix fublimations, it becomes entirely fimilar to native cinnabar. (yg) ~CINNABA of ANTIMONY. An artificial cinnabar may alfo be obtained from the decompofition of corrofive fublimate by antimony. ‘This operation is per- formed by mixing together and diftilling thefe two com- pound fubftances, The marine acid of correfive fublimate, which has a ftronger affinity ta regulus of antimony than to mereury, quits this latter fubftance to combine with the former, with which it forms a new compound called dutter * antimony, that pafles by diftillation into the receiver, ¢¢ BUTTER of ANTIMONY, | | fe) Hoffman fays, that cinnabar may be produced without fublimation, by tha ing or digefting a li Wi i ubl » by : g a little mercury-with volatile tinture of fulphur, by which means the mercury tos the ful. phur from the volatile pirit, and forms with it a deep red powder, the color of which is not inferior to that of ordinary cinnabar. © Alfq CINNABAR Alfo the mercury of the corrofive fublimate, being dif- engaged from its marine acid, unites with the fulphur of the antimony likewife difengaged from its regulus; and thefe two fubftances, thus united, are fublimed in form of cinnabar after the butter of antimony has been diftilled : but although in this procefs the mercury is not previoufly united with the fulphur into an ethiops, the fame ruper- fluity of fulphur is perceived in the cinnabar produced by this as by the former operation; becaufe the quantity of antimony neceflarily employed for the compleat decompo- fition of corofive fublimate, contains more than the requilite quantity of fulphur for the formation of perfe& cinnabar with the quantity of mercury contained in the corrofive fublimate. This inconvenience is to be remedied by the method directed in the former procefs ; that is, by repeating the fublimation till the cinnabar becomes perfect, and entirely fimilar to the native. It is called cianabor of anti- mony, becaufe its fulphur has been furnithed by antiruony. ‘The chief ufe of cinnabar is for painting. Although this body be compofed of fulphur, the color of which is a light citron, and of mercury which is white as filver, it is neverthelefs of an exceeding ftrong red color. Lumps of it are of a deep brown red, without brilliancy. But when’ the too great intenfity of its color is diminifhed by bruifing it and dividing it into finall parts, (which is 2 method gene- rally ufed to leflen the intenfity of all colors) the red of the cinnabar becomes more and more exalted, flame-colored, and exceedingly vivid and brilliant. In this ftate cinnabar is called vermiljon. Cinnabar is often employed as an internal medicine. Hoffman greatly recommends it as a fedative and antifpal- modic; and Stahl makes it an ingredient in his temperant powder. Other very intelligent phyficians, and particularly Mr. Cartheufer, deny that cinnabar taken internally has any medicinal quality. Their opinion is grounded on the unfolubility of cinnabar by any menftruum. This queftion concering the utility of cinnabar taken internally cannot be decided without new refearches and experiments. But cin- nabar is certainly ufed fuccefsfully to procure a mercurial fumigation, when that method of cure is proper in vcaereal difeafes. For this purpofe cinnabar is burnt in an open fire on red-hot coals, by which the mercury is difengaged, and forms vapors, which being applied to the body of the difeafed perfon, penetrate through the pores of the pie an CL. 4A ¥ and produce effects fimilar to thofe of mercury adminiftered en fumigations of cinnabar are applied, the ati ~ ought not to be expofed to breathe the ow of the a and of the burning fulphur, which might injure him. $e ERCURY and SULPHUR. (bh) CINNAMON. (i) CIVET. (4) CLAY, or ARGILLACEOUS EARTH, is a particular kind of ftrong earth, confiderable banks of which are found almoft every where, at greater or lef depths. Ke general properties and characteriftics of pure clay el 1. This earth makes no fenfible effervefcence with aci although it be capable of folution by acids, as we Fa ee. . 2. Clay being moiftened with water imbi that liquid, en and mixes with it, my 3- When it is mixed with no more than the necefla quantity of water to reduce it to a moderately foft pafte, it is fo ductile as to be capable of being worked upon a potter’s wheel, and of being formed in moulds. By thefe means ‘veflels may be made of it which keep their form. . 4 Clay is denfe, compad, and clofe. When its furface 3s rubbed with a polithed body, it alfo becomes polifhed. $5. If it be expofed when moift to a gentle heat, it gra dually dries and contralls; that is, its digenfions become lefs ; hence it is very apt to crack. (/) It retains moifture pretty ftrongly, and difficultly allows the laft portions of it to efcape. Velte : | (kh) Some native cinnabars, according to Bruckman ( Epiftol ltiner.) are fo hard, that the are i. and wrought like marble. ‘ PR emul ish (7) Cinnamon. From 16 oz. of the beft cinnamon fcarcely more than two fcruples and a half of effential oil can be obtained, This oil may be railed by diftillation with water, but fcarcely with fpirit of wine. The whole tafte and flavor of cinnamon may be extradted by digeftion with fpirit of wine, Neaman. 3 i Civer isan (odoriferous unctuous animal juice, foluble in i 5 fo 3 {pirit of wine, nor in water, even by means of: (1) Dr. Lewis found from experiments, that pure clay foften- ad with water to a due confiftence to be Andy upon a potter’s wheel, contratted by drying 44th part of every dimenfion, 6. If CLAY 6. If clay be heated much, and quickly, before it be per- fetly dried, it burfts with loud noife from the effort made by the water rarefied and changed into vapor, to efcape from the parts of this tenacious earth which invelop it. Thus this burfting and cracking do not happen, if the clay expofed to heat contain water enough to render it foft; be- caufe then the water finding much lefs refiftance from the clay, only feparates the argillaceous parts from each other, and efcapes with confiderable intumefcence. 7+ If pure clay, previoufly well dried, be expofed toa very violent fire, fuch -for example, as the fire of a glafs-houfe, it does not melt, and refifts much more than fand does the action of fluxes and vitrifying matters. By fire its parts are only very ftrongly agglutinated; and the mafs of cla thus calcined is called baked clay. During this baking it contralls in every dimenfion, and becomes as hard as flint, fo that it is capable of ftriking fire with fteel. 8. When clay has been thus baked by fire, it becomes no longer penetrable by water. If it be ground and levi- gated, it mixes with water as very fine fand does; that is, it does not form, as the crude clay does, a tenacious, duc- tile pafte, fit to be turned on a potter’s wheel. 9. Clay is entirely foluble in acids, and particularly in the vitriolic, with which acid it forms a vitriolic falt with an earthy bafis, which is true alom. See ALUM. 10. Laftly, clay, which, when unmixed, perfectly refifts the moft violent fire without fhewing any tendency to fufion, being mixed with equal parts of any calcareous or gypfeous earth, and with two parts and a half, or three parts of any fand or vitrifiable ftone, now becomes fufible, and difpofes the other two earths to fufion. All the properties which we have enumerated are effential to argillaceous earth, when perfe@ly pure; that is, when free from any mixture of heterogeneous matter. Clay fo perfectly pure has never yet been found in the earth. r. Macquer, in his Memoir upon clays given to the Academy in the year 1762, from which Memoir the greateft part of the prefent article is taken, obferves, that clay being an earth mifcible with water, is liable to mixture with many other matters, and that from this caufe we never find pure’ clay, which ought eminently and exclufively to pofefs the argillaceous properties, and which ought to be always the fame, without any peculiar differences; and laftly, that the only certain method of procuring this earth 18 to extract it from native clays, or from other bodies I which i ee arn an a EOP AE eT EK i i § y BL MEL 1 ; fy) HS bo it 5 Hi | jis BY Et hk a ii § Ne ff gh + HH Is i 111 | 3 § 1 Hi i i 1 4 sli * 3% 4 tl § 4 I) fi : | i a is St CLAY which contain it, by means of vitriolic acid, with which i forms alum ; and then to decompofe this alum by Er or alkalis, which difengage the vitriolic acid ; therefore properly f{peaking, earth of alum well prepared can be confidered as the only pure clay. Further, this earth has fo ftrong affinity with phlogifton, that we cannot expeét to obtain it perfely free from this principle. The general properties of clay, defcribed above, are therefore folely ap- plicable to this kind of earth. See the word Arum. Native clays poffefs more or lefs of thefe properties in proportion as they are lefs or more altered by mixture of heterogeneous matters. As clays are very ufeful in chemiftry, in arts, and in mat dinary life, we fhall mention fome important parts of knowledge concerning them; as, the methods of difcovering their purity, the places where they wy be found, and the means of purifying them. he purity of clays is known by the general properties above related. The more any native clay poffefles of thefe properties, the purer it is. The fubftances which hurt the purity of native clays are fand, phlogifton, bituminous matters, vitriolic acid, me- tallic earths, pyritous matters, calcareous earths, and mica. Inflammable matters alter the color of clay, which when pure ought to be white. Its color is affe@ed alfo by colored metallic earths, particularly by thofe of copper and iron and by all pyritous matters. : Clay, which is colored only by an inflammable matter which is not metallic, lofes its color by fire with accefs of air, and becomes white. Of this kind are moft grey and brown clays, of an uniform color, and not veined. Clays colored by pyritous matters, or by earths of iron or copper, are not rendered white b fire, till they are perfectly deprived of thefe metallic ear s. A certain quan- tity of thefe heterogeneous fubftances in clay render it fufible. Such clays are known by their colors, which are yellow, red, green, or veined, and marbled with feveral of thefe colors. They are the moft unfit of all clays for the making of utenfils intended to {uftain intenfe heat, fuch as chemical veflels, and the bricks, crucibles, or pots ufed in glafs-houfes, We may obferve, that cven the pureft native clays are hever entirely free from a mixture of fome parts of metallic, particularly ferruginous earth, Mr. Macquer, who has examined CLAY examined above eight hundred clays, fays, in the above quoted Memoir, that in all that number he did not find one, even amongft the whiteft, that was entirely pure and free from metallic matter : but when a very fmall quantity only of ferruginous earth is in clays; when it is not uni- formly mixed with them through all their mafs, which is known by a beautiful and pure white color, but is difperfed in fmall yellow fpots, as it frequently is; then fuch clays ought to be confidered as being of a very good quality. The only pra&ical method of feparating thefe ferruginous parts, is to break the clay into fmall lumps, and to cut out the yellow fpots. This ought to be done before the clay is mixed with water ; becaufe, by wathing, the ferrugi- nous parts are not feparable, but are more intimately mixed with the purer part of the clay. Pyritous matters, mica, and coarfe fand mixed with clays render them brittle, and diminith their ductility. Clays are eafily cleanfed from the greateft part of thefe hoferogs= neous fubitances by wathing ; that is, by misieg the clay well with much pure water, whi¢h is left to reft till only the fineft and lighteft parts of the clay remain fufpended in the water, the groffer parts having fubfided to the bot- tom : the water then is to be decanted off from the grofs fedi- ment, and pafled through a fine filken fearce : the fediment ‘which is depofited from this decanted and fifted water is the fineft and pureft part of the clay, and ought to be care- fully and cleanly collected and dried. This purification of clay by wathing is very neceffary when good pottery or porcelain is to be made. See PoTTERY and PoRrCELAIN. - The pyritous particles found in clays render them very fufible. A bit of pyrites left in clay which is expofed to a baking fire, always forms a cavity in the clay lined with a black leaden color. The wathing with water is an effeGual method of {epa- rating from clay even the {mallet particles of pyrites ; becaufe thefe particles have eflentially a fpecific gravity much greater than that of clay. But fand and mica are not fo eafily feparated from clay. Mr. Macquer has fthewn in his Memoir, that the moft careful wathing is infufficient for an entire feparation of fandy particles con- tained in clays; becaufe every native clay contains a con- fiderable quantity of fandy particles as fine and as light as the clay itfelf. Mica alfo cannot be feparated from clay for the fame reafon : but thefe fine partrcles of fand and mica, which cannoy CLAY cannot be feparated by wathing, do not injure works made of clay, but ate rather ufeful by preventing cracks in dry- ing and baking. Ses PoTTERY. "The particles of calcareous earths which injure the purity of many native clays, are eafily difcovered by the effer- vefcence which they make with” nitrous acid. ~ This kind of earth cannot be feparated from clays by wathing, from the finenefs and lightnefs of its parts. Clay containing a certain quantity of calcareous earth is by this mixture rendered fufible, from the fandy particles infeparable from the clay: hence all calcareous clays are improper for making utenfils intended to fuftain intenfe heat. Laftly, vitriolic acid, which appears to have been coms bined and. diftributed in a fingular manner by nature in all clays, may be feparated from them by digefting them in an alkaline liquor, and afterwards by edulcorating this clay with a fufficient quantity of water: but this purification of clays is not neceflary for moft purpofes to which thefe earths may be applied ; becaufe this acid is not injurious. Vitriolic acid mixed with clays renders them capable of decompofing nitre and common falt, and of difengaging the acids of thofe falts. Thefe extraneous matters being found naturally mixed with clays either fingle, or feveral together, and in all pro- portions, occafion a great variety of native clays. No earth has fo many different kinds; and undoubtedly from this great variety proceeds the multiplicity of names which are annexed to the feveral kinds of clay. The earths called boles, bolar earths, and Jealed earths, are true: clays. Thefe names have been chiefly applied to thofe clays which ftick ftrongly to the tongue, and alfo to certain clays filled with a large quantity of ferruginous earth, by which they are uniformly colored red or yellow. Other names are applied to clays from their particular ufes. Such are fuller's-carth, tile-earth, brick-earth, potter’ s-clay, pipe-clay, porcelain-clay. The earths called marles, as they are capable of dilution in water, have a certain degree of binding quality, effervefce with nitrous acid, are fufible with an intenfe heat, and appear to be nothing elfe than clays more or lefs fandy, and mixed with much calcareous earth. Laftly, epithets are given to many clays denoting their color, as white clays, grey clays, blue clays, €e. But thefe names communicate little knowledge on the true nature of the feveral native clays, A more particular examination CLYSSUS examination by chemical proofs is requifite to invefligate the heterogeneous matters with which different native i are mixed, the mixture of which alters the purity of fimple and primary argillaceous earth, to which they owe all they poflefs of argillaceous properties; then names might be given which fhould indicate their color and the heteroge- neous matters with which they are mixed, or at leaft thofe which prevail moft. Thus amongft thefe names we fhould have white, fandy, micaceous, or calcareous clays; grey or blue pyritous clays ; red or yellow Jerruginous clays ; black bituminous clays, &c. As our intention in this work is not to enter into the details of natural hiftory, we fhall fay no more upon this fubjet. What we have faid concerning the properties of pure clay, and the different 'fubftances which" alter jts purity, and more or lefs difguife the argillaceous properties of native clays, is fufficient to give a notion of the light which chemiftry can throw on natural hiftory in this and many other inftances. In Mr. Gellert’s table the fubftances capable of acting ° upon clays are fet down in the following order : Vitriolic acid, partly (fee an explanation of this word partly at the article ALum), liver of fulphur, fixed alkali, borax, calx of 554, calx of antimony, gypfeous earth, calcareous earth. CLOVES. (m) CLYSSUS. By the word clyffus are meant the vapors which rife during the detonation of nitre with any inflam- mable body. Thefe vapors may be colleéted and con- denfed into a liquor by a proper apparatus of veflels, The vapors refulting from the detonation of nitre with charcoal are called clyffus of mitre. ‘To prepare this clyflus, (m) Croves. The pungency of cloves refides in their refin, or rather in a combination of refin with effential oil ; for the {pirituous extra is very pungent; but if the oil and the refin contained in this extra® be {eparated from each other by diftilla- tion, the oil will be very mild ; and any pungency which it does retain proceeds from fome finall portion of adhering refin, and the remaining refin will be mfipid. © No plant, or part of any Plant, contains fo large a portion of eflential oil as cloves do. From fixteen ounces Neuman obtained by diftillation two ounces and two drams, and Hoffman obtained from the fame quantity an ounce and a half, This oil is fpecifically heavier than water, Neuman. y iE 0 i k in A. 1 i # ¥8 $i Ra a 8 | \ h i i £4. i E 9 g A Ig 3 1] J i Ai 14 ; 4 H H § [3 ir | Bl Bin dh te tech Sie SE oe te Ee NE Rs a eh a CLYSS US an earthen retort muft be employed capable of fuftaining 2 great heat applied fuddenly without injury. This retort, which ought to be alate, 1s to be placed in a furnace, and to it a very large balloon with a fmall hole is to be adjufted. When the bottom of the retort has become red-hot, a fmall quantity, that is, a dram and a half, or two drams, of a mixture of purified nitre and charcoal powder, is to be thrown into the retort through the tubulated part, which muft be immediately afterwards clofed ; the nitre then detonates, and the vapors are condenfed in the receiver. Other parcels of the detonating mixture are to be thrown in fucceflively with the fame management, till a fufficient quantity of liquor is colle@ed in the receiver. = If, inftead of charcoal powder, fulphur be employed to detonate with nitre in clofe veffels, the liquor obtained is called clyffus o Sulphur 5 and if antimony be employed to detonate with mitre, the liquor is called clyfis of antimony. The old chemifts, who practifed thefe operations, be- lieved that the liquors thus obtained had particular virtues for alchemical purpofes. For this reafon, they made this preparation with great apparatus and trouble. But now, when chemical operations are better underftood, thefe liquors are believed to have no virtues. The clyflus of nitre is made in laboratories, not for any ufe to which it can be applied, but to eftablifh a theory concerning the nature of nitrous acid, and to prove that this acid is entirely deftroyed and decompofed by detonation. For, when the operation is finithed, nothing is found in the retort but the alkali which was the bafis of the nitre ;’ and the liquor contained in the receiver has no acid tafte, does not redden the tin@ure of turnfol, makes no effer- vefcence with alkaline matters, and is truly ‘nothing but water, which is fometimes flightly alkaline, becaufe the force of detonation is capable of raifing fome {mall part of the alkali of the nitre. ~The clyflus of fulphur is acid, becaufe the vitriolic acid of the fulphur is not decompofed, as the nitrous is, by . combuftion, but is difengaged and fet at liberty by the burning of the phlogifton of the fulphur.” Befides, one part of this vitriolic acid when difengaged a&s upon the ‘hitre, forms with its bafis a vitriolated tartar called Glafer’s fal polychreflum, and difengages the nitrous acid. This portion of nitrous acid thus difengaged by the acid of ful- phur, and which is no longer retained and fixed by an alkali, is CLYSSUS is not capable of inflaming with phlogifton : wherefore it is not decompofed, and, together with the vitriolic acid which “is not fixed by the alkali of the nitre, makes part of the clyflus. The clyflus of fulphur appears then to. be compofed, 1. Of a part of the nitrous acid deftroyed by inflammation with the phlogifton of the fulphur : 2.” Of another portion of nitrous acid which is not decompofed, but js difengaged by the acid of fulphur: 3. Of all the acid of {fulphur which does not unite with the alkaline bafis of the njtre. The clyflus of fulphur muft differ confiderably according to the proportions of nitre and of fulphur employed. If a little nitre be added to much fulphur, the oft will be almoft all pure acid of fulphur. An Englifh chemift *, fome time ago, found a method of obtaining very advantageoufly the vitriolic acid of ful- phur, by burning fulphur in clofe veflels with a fmall quantity of nitre. This method of decompofing fulphur tor the extraction of its acid is faid to be executed in great, and to be the caufe of the great reduction of the price of that acid within thefe few years paft. This is an in- ftance of practical utility from a clyflus ; for the vitriolic acid obtained by detonation of nitre in clofe veffels is a true clyflus of fulphur. The clyflus of antimony is fimilar to that of fulphur; for the nitre in this operation chiefly detonates with the {fulphur of the antimony : however, the phlogifton of the metalline part of the antimony contributes alfo to the detonation, Bsfides, fome flowers of antimony are mixed with this clyflus. Several neceflary precautions ought to be taken to make this operation of a clyflus fucceed, and to avoid accidents 3 for the rapidity and violence with which nitre detonates in certain circumftances may occafion a ftrong explofion and fupture of the veflels. “To prevent thefe accidents, the inflammable matters ought not to be very well mixed with the nitre, becaufe the detonation is proportionably ftronger and quicker as the mixture has been made more exactly, Alfo, a: {mall quantity only of the mixture ought to be detonated at once, and another quantity fhould not be added till the detonation of the former be finithed. See NiTRE, DeTonaTiON of NITRE, and GuN-PowDER. - * Dr. Ward. See Srir1T of Surpnur, Q 2 COA- C OC A LL COAGULATION. This term is employed by chemifts to denote certain operations in which fluid bodies become folid ; for inftance the cryitallization of falts. See CRYSTALLIZATION. COAGULUM. This Latin word is ufed to fignify curdled concretions formed by the mixture of two liquors, fuch as the precipitate of filver in the formation of luna cornea, the offa Helmontii, the miraculum chemicum, and many others. See thefe words. COAL. By the word coal is meant any fubftance containing oil which has been expofed to fire in clofe veflels, fo that all its volatile principles are expelled, and that it can fuftain a red heat without further decompo- fition. Coal is a body folid, black, very dry, and confider- ably hard. J | ‘The fpecific charaller of perfe& coal is its capacity of burning with accefs of air, while it becomes red-hot and fparkles, fometimes with a fenfible flame which gives little light, no fmoke or foot capable of blackening white bodies. Coal is capable of communicating its inflammable pria- ciple either to the vitriolic acid, with which it forms fulphur ; or to the nitrous acid contained in nitre, with which it inflames ; or to metallic earths, which it reduces into metals. But the phlogifton cannot pafs from coal to form thefe new combinations without the affiftance of red-heat. Coal feems to be an unalterable compound in every in- Aftance but thefe mentioned, of burning in open air, and of communicating its phlogifton to other bodies: for it. may be expofed in clofe veflels to the moft violent and continued fire without fuffering the leaft alteration. No difpofition to fufe, nor any diminution of weight can be perceived. It is a fubftance exceedingly fixed, and perhaps the moft refrac- tory which is known. o change is produced upon coal by air or by water, nor by the moft powerful menftruums of chemittry, except- + ing perhaps by particular proceffes. A trial might be made whether the concentrated. mineral acids, or cauftic alkalis, would not, when affifted by heat, make fome alteration upon coal in along time. The younger Mr. Rouelle propofed as a problem, in the’Journal de Medicine for O&ober, 1762, to diffolve vegetable coal in the palm of the hand. Why he propofed it as a problem we do not know; fince he adds, that Mr. Wolf has refolved it, and that this folution my C0 AL. be made by liver of fulphur. He has not explained whe- ther he means the folution of all the fubftance of the coal, or of its phlogifton only. Coal is evidently a refult of the decompofition of the compound bodies from which it is obtained. It confifts of the greateft part of the earthy principle of thefe compound bodies, with which a part of the faline principles, and fome of the phlogifton of the decompofed oil are fixed and combined very intimately. Coal can never be formed but by the phlogifton of a body which has been in an oily ftate : hence it cannot be formed by fulphur, phofphorus, metals, nor by any other fubftance the phlogifton of which is not in an oily tate. Alfo every oily matter treated with fire in clofe veflels furnifhes true coal; fo that whenever a charry refiduum is left, we may be certain that the fubftance employed in the operation contained oil. See O1L. Lafily, the inflammable principle of coal, although it proceeds from an oil, is certainly not an oil, but is pure phlogifton ; {ince coal added to vitriolic acid can form fulphur, to phoiphoric acid can form phofphorus, to me- tallic earths can form metals, and can detonate with nitre ; and fince oil can produce none of thefe effelts, till it has been decompofed and reduced to the ftate of coal. See SvrrHur, PHospuorUs, METALS, Ni1TRE, and OIL. Befiles, the phenomena accompanying the burning of coal are different from thofe which happen when oily fub- ftances are burnt. The flame of charcoal is not fo bright as that of oil, and produces no fmoke or foot. All the phlogifton of coal is not burnt in open air, parti~ cularly when the combuftion is flow. One part of it exhales without decompofition, and forms a vapor, or an invifible and infenfible gas. This vapor, or this phlo- gifton, difengaged from coal, is very pernicious. It fo affects the brain and nerves as to occafion inftant death. For this reafon, to remain in a clofe place where charcoal or other coal is burnt, is dangerous. Perfons ftruck b vapor of charcoal are ftunned, faint, fuffer a violent head- ach, and fall down fenfelefs and motionlefs. If they are yet alive, the beft method of recovering them is to expofe them as quickly as is poffible to open air, and to make them fwallow vinegar, and breathe its fteam. Acids, and parti~ cularly vinegar, feem to have a property of fixinz and reftraining in fome fort the action of phlogifton, and of the vapors > volatile inflammable matters, which produce Q 3 fimilar CO A'L . fimilar effes on animals. For this reafony vinegar dimi- . nithes the accidents of intoxication occafioned by fpirituous liquors and by opium. . The vapor which exhales from liver of fulphur, particularly when a large quantity of it is decompofed by an acid, and the vapors which exhale from matters undergoing the fpirituous or putrid fermenta- tion produce the fame accidents as the vapors of coal, and are remedied by the fame means. Amongft coals, fome differences are obfervable, which proceed from the difference of the bodies from which the are made; particularly, fome coals are more combuftible than others. This combuttibility of coals feems to de~ pend on the greater or lefs quantity of faline principle contained in coal ; that is to fa » that the more it contains of faline principle, the more exiiy it decompofes and burns. For example, coals made of plants and wood, containin much faline matter capable of fixing it, the afhes of which contain much alkaline falt, burn vigoroufly and produce much heat ; whereas the coals of animal matters, the faline principles of which are volatile, and cannot be fixed but in {mall quantity, and the athes of which contain little or no alkaline falt, are fcarcely at all combuftible. For they not only do not kindle fo eafily as charcoal does, nor ever burn oo but they cannot be reduced to afhes without very great trouble, even when the moft effeGtual methods are ufed to facilitate the combuftion. | I have kept the coal of bullock’s blood very red-hot in a fhallow crucible, furrounded ‘with burning charcoal, fix hours and more, and flirred it conftantly that it might all be expofed to the air, but I could not reduce it to white or even grey afhes. It remained fill very black and full of phlogifton, The coals of pure oils, or of concrete oily fubftances, and foot, which is a kind of coal raifed during the inflammation of oils, are as difficultly burnt as animal coals. Thefe coals contain very little faline matter, and their afhes furnifh no alkali. Thefe coals, which are fo difficultly burnt, are alfo lefs Capable of inflaming with nitre than others more com- buftible ; and fome of them even in a great meafure refift the a&ion of nitre. The refraltory quality of coals is a fingular property, his property is in fo great a degree, that they are found to be the fitteft {ubftances for f upporting bodies expofed to the focus of large burning-glaffes. Neverthelefs all coal is com- poled C.OATING earth which is not perfeitly refraltory, of a poet a which is fufible and affifts the fufion of other fubftances, and of phlogifton which is certainly the prin-. ciple of the fufibility of metals, as their earths become fo much more difficult to fufe as they are more dephlogifti- Le 1 ie : iy (FOSSIL). (0) : COATING. (p) CORRE: we * ake charcoal, or vegetable coal, pieces of wood are fo 5 Wid to form a le ererally conical, which ple i covered with turf to prevent the too free draught of air, by w iy the wood would be reduced to afhes and not to coal. The pile is then to be kindled, and the fire is to be continued till all the watery and the more volaiile parts of the wood are diflipated; that = till no more {moke arifes, at which time the wood is Shoroagh- ly red-hot. The external air is then to be totally excluded, by covering the pile with earth, and thus the fire is extin- BA as (Fossir), or Pit-Coav, is a black or brown, laminated, bitumincus fubftance, not very cafily inflammable, but which once inflamed, burns longer and more intenfely than any other fubftance. Of this fubftance three kinds are diftinguifh- ed by authors. The refiduum of the firft after combuttion is black ; the refiduum of the fecond is fpongy, and like pounce fone; and the refiduum of the third 1s whitifh afhes. ~ Some foffil coal, by long expofure to air, falls into a greyifh powder, from which alum may be extracted. Foffil coal by diftillation yields, 1. a phlegm or water; 2. a very acid liquor; 3. a jain oil like naphtha ; 4. a thicker oil, refembling petroleum, whic falls to the bottom of the former, and which rifes with a violent fire; 5. an acid concrete falt; 6. an inflammable earth remains in the retort, Thefe conftituent parts of foffil coal are very fimilar to thofe of amber and other bitumens. See Bitumen. For the exciting of intenfe heats, as of furnaces for {melting iron- ore, and for operations where the acid and oily vapors would be detrimental, as the drying of malt, fofiil coals are previoufly charred, or reduced to coats; that is, they are made to under go an operation fimilar to that by which charcoal is made. By his operation cals are deprived of their phlegm, their acid liquor, and of greateft part of their fluid oil, Coaks therefore con- filt of the two moft fixed conftituent parts, the heavy oil and the earth, together with the acid concrete falt, which though volatile is detained by the oil and earth. : ee {(p) Coating, or LoricaTiON, is an application o day, or mixture of clay with fand or other fubftance, to the external or internal furfaces of chemical veflels, to guard them againit the gy Q 4 effets Tad H } i { aE 1 | ; : Hil 4 Aid i , 8 3 k 1 ii i 4 i 1 1 Se gh 2 HE i 4 Li A Hea i i 1 i i L ii } | aa 4 f t i i { 3 I — A ———— texture and friable. ‘2. The fj COB a ig Op COBALT. This name is given by authors to fevera different minerals. We fhall here only talk of that kind of cobalt which contains the metallic matter whofe calx fur- nifhes a blue glafs when vitrified ;. becaufe the name cobalt ought to be confined to this mineral alone, to avoid’ the uncertainty and confufion too frequent in names of natural hiftory and of chemiftry. RS i iri ok Cobalt is a very heavy mineral, of no determinate figure; , of a grey color, more or lefs brilliant; of 2 fine, compa&t, clofe grain, the furface of which, when it has been expofed to the air, is covered with a powder, or efflorefcence of the color of a peach-bloffom. aay. a his mineral is not found in many places. Hitherto it feems to have been found only in Saxony and in the Pyre- hiean mountains (g). It contains feveral fubflances mixed oy Wo ae ond effe@s of fudden heat, or of the corrofive quality of the matter to be contained. Thus glafs retorts intended to be expofed to what 1s called a naked fire, that is, to a fire without interpofition ‘of a fand-bath or other fubftance, ought to be externally coated, by which means they will not be fo lable to be cracked by the fudden application of heat and cold. Retorts may be coated in the fol- lowing manner: Take of clay and fand equal parts ; make them into a thin pafte, with freth blood prevented from coagulating by agitation till it be cold, and diluted with water 5 add to this pafte fome ‘hair and powdered glafs ; with a brufh dipt in this mafs befmear the retort; and when this firft layer is dry, let the fame operation be repeated twice or oftener, till the coat applied be about one-third part of an inch thick, For the compofitions for coating crucibles, furnaces and other inftruments made of plate. iron, Jee CrucCiBLE. : > A . (7) Cobalt has been found in Cornwall, Scotland, and pro- bably in other parts of Lurope. “That it is in.the eaftern parts of Afia, appears from the blue coloring on'old oriental porcelain, Probably alfo the mines difcovered in thefe countries are nearly exhaufted; ‘as confiderable quantities of zaffre and fmalt are ex. ported from Europe to China, Befides the grey or afh- colored cobalt defcribed in the text, which is the moft ‘frequent, other cobalts “are found’ of various colors and textures, mixed with various fubftances. ~'‘Wallerius enumerates fix fpecies of cobalts. 1. The a/b-colpred ore, which is regulus of cobalt mineralifed by arfenic, confifting of thinin g leaden- colored grains. “Some ores of this kind are compa, refembling fteel, and others are of a loofe ) ecular ore is black, thining like a mirror and laminated. This {pecies is very rare, and is fuppofed by Wallerius to be a foliated fpar, or felenites mixed with ore of Rs nt Se win ta =, sans cobalf COB A PBT and confounded together, and in this refpe@ fome cobalts differ ‘from others.” All of them contain fulphur, much arfenic, and the femi-metal the calx of which may be made into blue glafs, and which Mr. Brandt of the Swedifh Academy calls ‘Regulus of Cobalt when it is reduced to its metalline ftate. ~Befides thefe fubftances, fome cobalts | contain bifmuth, filver, or both of thefe. Of all thefe matters, the peculiar regulus of cobalt renders this mineral valuable from the fine blue which is manufac- tured from it, and which is the only blue that can be ufed in vitrification. : Neverthelefs other fubftances are colle®ed from cobalt in the operations praétifed on it, but only fecondarily, becaule thefe fubftances may be obtained without additional labor or expence. For example, as it is necefiary in the preparation of the blue to expel the arfenic, this mineral muft be expofed to long roaftings; inftead of diffipating the arfenic which rifes in vapors during the torrefaction, it is collected in long crooked chimneys, adapted to the furnaces in which the cobalt is roafted, and thus is obtained almoft all the arfenic which is fold in commerce. See Arsenic. © _ Likewife after the roafting, when the calx of cobalt is fufed with vitrifiable matters to make the blue glafs called gmalt, the bifmuth and filver may be feparated and col- lected. Hee | cobalt. 3. The witreous, or flag-like ore, is of a blueith, fhining color, compa&, or fpongy. 4. Cryftallized ore of cobalt is a grey, deep-colored ore of cobalt, confifting of clufters of cubical, pyra- midal, prifmatic cryftals. 5. Flowers of cobalt, red, yellow, or violet. * Thefe flowers feem to be formed from fome of the above defcribed compact ores, decompofed by expofure to moift air. This decompofition is fimilar to that which happens to ferruginous and cupreous pyrites. 6. The earthy ore of cobalt is of a greenifh white or of a yellow color, and of a foft and friable texture. This fpecies feems to be an ochre of cobalt, and is formed perhaps from the flowers of cobalt further decompofed, in the fame manner as a martial ochre is formed from the faline eflorefcence of decom- pofing pyrites, when this efflorefcence is further decompofed by expofure to moift air ; by which the vitriolic acid contained in it is expelled, and the eflorefcence is changed from a faline ftate to that of an ochre or calx. Befides thefe proper ores of cobalt, it is alfo found in a blue clay along with native filver, in ores of bifmuth, and in the mineral called kupfernickel, Se Nic- BEL, The COHESION The filver, although a valuable metal, is generally in fo fmall a quantity, that it would net be worth the trouble of obtaining on purpofe from this mineral. The cobalt is therefore always operated upon for the fake of the blue. If well-calcined cobalt be treated with phlogifton and fluxes, like other metallic calxes, it will be reduced to a femi-metal, called by Mr. Brandt, who firft difcovered it, e Regulus of Cobalt. gx ee and alfo the calx of cobalt, amongft other fingular properties, has that of making a very curious fym- pathetic ink, by being diflolved in aqua regia. See, for what Jurther relates to cobalt, the articles SMALT, ZAFFRE, AZUR, Recurus of CosaLT, Ink (SYMPATHETIC). COCHINEAL. (s COERULEUM {fonTaNUM. (s) COHESION. By cohefion is meant the adhefion which the integrant or the conftituent parts of bodies have to each other. (r) Cocuinear. From an ounce of cochineal Neuman. obtained by diftillation two feruples of hlegm, four fcruples of urinous fpirit, fifteen drops of oily fpirit, twenty-two grains of volatile alkali, five {cruples and two grains of empyreumatic oil, and two drams and two fcruples of a refiduum containing five grains of fix lixivial falt. The fame author found that of four .drams of cochineal, three drams were foluble in water, and ly as much in {pirit of wine. : R i Aiea or boiled with water produces a crimfon tinc- tare inclining to purple. Fixed alkali renders the crimfon deeper, but leffens its luftre. Volatile alkali heightens the color without diminution of luftre. The beft method of applying volatile alkali for this purpofe in dying was found by Mr. Hellot to be, by dipping the cloth dyed with cochineal in a folution of fal aspmio niac, and then throwing into the {olution fome potafh, by whic the volatile alkali of the fal ammoniac is difengaged. By a {mall quantity of vitriolic acid the crimfon decoftion of cochineal is rendered purple, by more of that acid it is rendered flefh-colored, and by ftill more colorlefs. This colors firft changed toa yellow, and afterwards deftroyed by nitrous acid. Solution of tin in Ses regia heightens the color of this decoction to a {carlet. Reem dyers give a fcarlet tinge to this decoftion by turmeric ; but ke tinge does not penetrate the cloth, and is not durable. See DS sivisvi MoNTANUM, mountain-blue, called by fome authors chryfocolla, isa blue ore of copper. See Ores of Cor- PER, COHO™ COLCOTHAR COHOBATION. Cohobation is an operation by which the fame liquor is frequently diftilled from the fame body, either with an intention to diffolve this body, or to" produce fome change upon it. This is one of thofe opera- tions which the ancient chemifts pra@ifed with great patience and zeal, and which are now neglected. To make this operation eafier, and to prevent the trouble of frequently changing or moving the veflels employed, a particular kind of alembic is contrived, very convenient and well adapted, called a Pelican. See PELICAN. COLCOTHAR. Colcothar is the fubffance which remains from the calcination and diftillation of martial vitriol with a violent fire, Vitriolic acid does not adhere fo ftrongly to the iron of the martial vitriol as to be capable of refifting the action of a ftrong fire ; therefore when this vitriol js heated intenfel and during a long time, it lofes more and more of its i which is diffipated if the calcination be performed in open veflels, and which may be diftilled with a proper apparatus. When the vitriol lofes its acid, it acquires a red color, and becomes an earthy matter. The calx of iron, whether it has been deprived of phlogifton by fire or by acids, is always of this red color: but the iron contained in vitriol fuffers this alteration during the calcination. When the calcination is finithed, what remains of the vitriol has ftill fome tafte, and even the property of becoming moift ‘when expofed to air. 'Thefe qualities are caufed by fome remain- ing acid which adheres obftinately to the earth of the iron, and which the fire could not expel. As this acid is very much concentrated, and is not combined with the calx of iron in the colcothar, as it was with the iron itfelf in the vitriol, becaufe the phlogifton of the iron is loft by calci- nation, we need not wonder that this calcined vitriol fhould powerfully imbibe méifture from the air, although the un- calcined vitriol does not. This remaining acid may be taken from the colcothar by wathing with water. The colcothar then has mo tafte, does not attra& moifture from the air, and is called Sweet Earth of Vitriol. Unwathed colcothar is ufed in medicine, but only exter- nally. It may be properly applied to all putrid, fanious and fungous ulcers, becaufe it is antifeptic, ftrongly tonic, aftringent, and even corrofive, from its remaining uncom- bined vitrilic acid. S¢¢ ViTRIOL (MarTIAL) 0nd CAL- CINATION, COLO- COMBUSTION COLOPHONY. Colophony, or rofin, is the refi nous refiduum after the diftillation of the light oil from tur» pentine, It has alfo the properties of other refins, and the fame principles may be obtained from it by analyfis. See Barsams (Native); TURPENTINE ; and REsIN, COLORS. (t) COMBINATION. By the word combination, we ought to underftand the union of two bodies of different natures, from which a new compound body refults, For example, when an acid is united with an alkali, we fay that a combination betwixt thefe two faline fubftances takes place, becaufe from this union a neutral falt refults which is com- pofed of an acid and an alkali. §e¢e ComposITION. COMBUSTION. Combuftion is nothing elfe than the difengagement of the inflammable principle contained in feveral kinds of bodies, which are therefore called com- buflible. : The principle of inflammability is united in greater or lefs quantity with bodies, and in feveral different manners ; hence the diverfity occafioned in the phenomena of com- buition. If the phlogifton of a body be in large quantity, and in an oily ftate, this body is very ¢ombuftible, and burns with a bright flame, accompanied with fmoke and foot. Wood, 59 Hovis refins, oils, fat, are combutitible bodies of this nd. If the phlogifton of a body be not in an oily ftate, but in large quantity, or not very intimately combined, this body may alfo be very combuitibie, and may even burn with flame. But this flame is flighter and generally lefs lumi- nous than the flame of oily bodies; befides, it is accompa- nied with no fmoke or foot. Spirit of wine, fulphur, phofphorus, charcoal, fome metallic matters, and particu- larly zinc, are combuftible bodies of this kind. The flames of phofphorus and of zinc are neverthelefs very luminous. Laftly, bodies containing phlogifton which is not in an aily ftate, and which is in fmall quantity, or ftrongly com- bined with other uncombuftible principles, burn difficultly without any fenfible flame; fuch are certain animal coals, foot, afhes of vegetables containing very little phlogifton, and imperfect metals. The grand principle concerning combuftion in general is, that no combuftible matter can burn without accefs of air, (t) Colors. See BLack, BLug, &¢. and DvinG, and COMBUSTION and that the more immediate its conta with air is, the more rapid and complete is its combuftion. §ee Air. For this reafon, even the moft inflammable bodies, as fpirit of wine and ethereal oils, do not burn but at their furface, becaufe that only is expofed to air. For the fame reafon, inflammable bodies, when reduced to vapor, burn rapidly and inftantaneoufly, becaufe they are all expofed to air at once. Laftly, for the fame reafon, fome bodies, though full of phlogifton, fuch as fat, oils, &c. cannot burn without a heat fufficient to reduce them into vapor. The practical methods of promoting, accelerating, and of completing the combuftion of the inflammable princi- ple of bodies may alfo be naturally deduced from what we have faid on this fubject. Thefe methods confift in apply- ing as much of thefe bodies as poffible to the air. Thus by dire€ting a current of air upon the burning bodies, their combuftion is accelerated and augmented in proportion as this current is flronger, as the effets of bellows and air- furnaces evidently prove. : Mott oily ‘bodies, as wood, burn with much flame, which lafts while any fenfible quantity of oil remains : after which the flame ceafes. "They are not however yet deprived of all their inflammable principle, a part of which remains in the ftate of coal. Then the remaining part of the body may continue to burn, if it contains much phlogifton, but without a luminous flame, and in the manner of charcoal. In proportion as the phlogifton is confumed by this fecond combuftion, what remains of it becomes more and more difficultly combuftible; not only becaufe the leaft fixed and adherent part of it is firft burnt, but alfo becaufe the proportion of incombuftible matter, to which this phlogifton is united, becomes greater and greater. Hence when this combuftion has arrived at a certain point, that is, when a fmall portion of phlogifton only remains ftrongly combined, and alfo covered and defended by a large quan- tity of incombuftible matter, this remaining phlogifton will not burn alone, and is nearly in the fame ftate as that of moft metallic matters. If, therefore, this combuftion is to be compleated, which then is called calcination, fire muft be applied from fome other fuel, with which the body to be calcined or dephlogifticated is to be penetrated, and kept red-hot ; and as much air is at the fame time to be applied to the body, till no longer any marks appear of its inflam- mable principle. Afhes of vegetables, foot, coals of oi an | a HEE | i i fis : ie i COMPOSITION and of animal matters, and feveral metallic fubftances, cone tain fome phlogifton in this laft fate, When the phlogifton of thefe fubftances is to be entirely burnt or diffipated, all the means capable of favouring combuftion ought to be made to concur. The fubftances ought to be firft divided into very {mall parts, becaufe then they prefent more furface to the air than when in one mafs. They are then to be expofed to the action of fire in a convenient veflel, fo that the ajr may have free accefs; as for example, in a wide-mouthed teft, and under a muffle open on the fide at which air is introduced into the furnace, To accelerate further this operation, a current of air may be direGted upon the furface of thefe bodies, and they may be frequently ftirred, that all their parts may be fucceffively prefented to air. The ftrongeft fire which the matter can fuftain without fufion ought to be applied ; becaufe a melted body forms always one mafs, and prefents lefs furface than when it is’ divided in final] detached parts. Thus fufible bodies, as athes, alkaline falts and metals, ought to be i with a moderate heat, and proportioned to their fibility. The Ja portions of the phlogifton of certain bodies are fo difficultly combuftible, that notwithftanding all thefe means united, they never can be entirely burnt, Some of them even, as the perfect metals, are confidered as bodies entirel incombuftible, becaufe they can fuftain the moft violent fire during entire months, without fuffering any fenfible alteration. Neverthelefs, Junker affirms, that gold and filver may be calcined, if they are treated during fix months, by reverberation, in the manner of Ifaacus Hollandus. Although the certainty of this experiment has not been fufficiently confirmed by repeated trials, the method of calcining thefe metals propofed by this chemift agrees fo well with the great principles of combuftion, that its fuccefs feems very probable. See CavrciNvaTION. COMPOSITION of BODIES. Chemical com- pofition is the union and combination of feveral fubflances of different natures, from which a compound body refults. From this union of bodies of different natures a body is formed of a mixed nature, which Becker and Stahl have called a mixture, and which may be called a combination or chemical compofition, to avoid the equivocal fenfe of the word mixture, by which may be underftood only a mere inter- pofition of parts, and ‘which therefore would give a very 2 {alle CONCENTRATION falfe idea of chemical compofition, in which 2 mutual dheffon takes place between the combined fubftances. : When the Korner confidered by chemifts as fimple, or primary principles, are combined together, they form the firft compounds, to which Becker and Stahl give, by vey of excellence, the name Mixts. The fame chemifts the bodies formed from the union of thefe mixts, compounds. When they treat of more complicated combinations, they talk of decompounds and furdecompounds. ; This diftribution of bodies, more or lefs compounded, is jut and conformable to experience. But the names given by Becker and Stahl are not fufficiently clear and accurate. A more fimple and clear method of diftinguifhing thefe feveral claffes of bodies feems to be by numbers indicating their degree of compofition. Thus we might fay, compounds of the firft, of the fecond, of the third degree, &c. as Mr. Macquer propofes in’ his courfe of chemiftry. CONCENTRATION. The concentration of a body confifts in approximating its proper and integrant parts, by taking away fome fubftance interpofed betwixt thefe parts, and which is extraneous or fuperabundant to the body to be concentrated. Thus, for inftance, a folution of any faline fubftance in water may be concentrated by expelling part of the water of this folution. But cuftom has applied the word concentration to the dephlegmation of acids, and particularly of vitriolic acid by diftillation, and of vinegar by congelation. We proceed to both thefe con- centrations. CONCENTRATION #VITRIOLIC ACID. Vitriolic acid, procured either from vitriol or from fulphur, is never fufficiently pure for chemical operations. It al- ways contains fome extraneous fubftances from which it muft be purified. p The heterogeneous matters which chiefly affect the pu- rity of vitriolic acid, are fuperabundant water by which it is weakened, and inflammable matter by which it is render- ed black and fulphureous. Thefe two fubftances are fepa- rable by one and the fame diftillation, which is called the concentration, or the rectification of vitriolic acid. ‘This acid ought to be’ diftilled, whether it be both watery and ful- phureous, or have only one of thefe faults. To explain what paffes in this operation, and the ma- nagemeut which muft be obferved, we will firft confider what happens in the concentration of vitriolic acid, which is only diluted with fuperabundant water, and not phlo- gifticated. CONCENTRATION -gifticated. We will then proceed to the changes produced upon this acid by diftillation, when it is fu: ciently free from water, and is only phlogifticated. od 1 , When vitriolic acid, diluted with fuperabundant water, is to be concentrated, if it contains a confiderabl® quantity «of water, it may be difengaged from the greateft part of this fuperfluous water in ftone or glafs bottles, without the apparatus of diftillation. The greater the quantity of water which is united with the vitriolic acid, the lefs firongly does a part of it adhere. As this water is much more volatile than vitriolic acid, it evaporates by almoft the fame degree of heat which is requifite to the evapora- tion of pure water. While the water exhales, the parts of the vitriolic acid remaining in the veflel are approximated, and the acid becomes more and more concentrated and ftrong. Thus the operation proceeds very well to a certain point, and even better than by diftillation. But when the acid has arrived at a certain degree of concentration, it cannot be completed in open veflels ; becaufe.the fmaller which the quantity, is of water united to the acid, the more {trongly it adheres ; (0 that it cannot be feparated without a heat fufficient to raife alfo the acid, which therefore in open veflels would be loft. But another and more remark- able inconvenience occurs, which is, that when vitrio- lic acid begins to be much dephlegmated and very ftrong, it becomes fo greedy of moifture that it attra®s that of the furrounding air, as Mr. Beaumé has well obferved, and perpetually combines with it ; fo that we inftant it refumes es as much water from the air as it lofés by evaporation. The concentration of this acid muft therefore be coms pleted in clofe veflels by diftillation. For this diftillation, a retort of good glafs, capable of refifting acids, muft be filled half full with the vitriolic acid to be concentrated, and fet in a fand-bath covered en- tirely with fand. After a receiver has been adapted to it, heat muft be applied, and very gradually augmented till drops are diftilled. If the vitriolic acid contains little water, the diftillation does not begin but with a confiderable degree of heat, and the drops which fall into the receiver are very acid. Thefe drops fall very flowly, and the diftillation muft not be too much haftened. As the concentration advances, the drops follow each other at longer intervals, although the acid contained in the retort acquires more and more heat. To- ‘wards the end of the operation, and when the acid is much con CONCENTRATION concentrated, .care muft be taken not t6 encreafe the heat fo much as to make the acid boil, which cannot be effected with lefs thana red heat. By this heat all the acid may be raifed at once, in drops and burning vapors, which pafs precipi- wel, and generally burft the retort. i hen this accident happens, whether it proceeds from haftening the diftillation too much, or from cold air ftrik- ing the retort, the concentrated and burning acid is almoft entirely reduced to white; thick, fuffocating vapors which inftantly fill the laboratory. The operators ought to re- move themfelves from fuch hurtful vapors, NE The duration of this operation, and the quantity of phleg- matic acid to be diftilled, fo that the vitriolic acid thall be left highly concentrated, are abfolutely indeterminate, as the depend on the degree of ftrength which this acid had be- fore its concentration. The vitriolic acid, which was formerly kept by druggifts, required that one half of jt fhould be drawn’ off by diftillation to make the remaining part twice as heavy as water. At prefent, it is much Benger, 2jthouch Chgaser. Some may be got very con- centrated, and which only requires to be dephlogift; i the manner defcribed Hl Pog The vitriolic acid manufaQured in the great, and fold in commerce, is always mixed with more or lefs inflammable matter, by which it is rendered black and opake. It ma be entirely difengaged from this extraneous matter by 2 diftillation fimilar to that above defcribe _ The firft portions of fuch an acid which paffes in diftilla- tion are a very penetrating, volatile, fulphureous acid. If the phlogifticated vitriolic acid which is rectified be alfo phlegmatic, the diftillation may be fo managed that the liquor fhall flighty boil. This liquor continues black tl] 1t 1s concentrated to a certain degree; when by help of a ftrong heat which it then acquires, the concentrated acid acts upon the inflammable matter, diffipates it, or com- pletely burns it. The liquor in the retort becomes gra- dually clearer, and at length perfectly white and tranfpa- rent, If this acid has alfo the requifite degree of concen- tration, the operation is finithed when the liquor thus be- comes perfectly white and tranfparent. The retort muft be left in the fand-bath till it is'cold, and then the acid is to be poured into a clean, dry, cryftal-glafs bottle ; becaufe the - {malleft piece of inflammable matter is capable of phlo- gifticating and blackening re&ified vitriolic acid ; and be. caufe ny moifture, befides weakening the acid, might occa- You. 1. R fon CONCENTRATION fion fuch heat as to break the bottle. When the acid is poured into the bottle, the neck of this bottle ought to be wiped dry, and clofed by a glafs ftopper, accurately fitted and well wiped. The mouth of the bottle ought alfo to be + guarded from duft by being covered with leather. The phlegmatic or fulphureous liquor, which pafled over into the receiver, is called Spirit of Vitriol. It is clear and white, and may be ufed in many operations where concen- trated vitriolic acid is not requifite, or it may be concentrated and rellified. CONCENTRATION of VINEGAR by CON- GELATION. Vinegar produced by the acetous fer- mentation is a vegetable acid much ufed in chemiftry. As this acid is mixed with much extraétive matter and fuper- abundant water, chemifts have endeavoured to render it more pure and ftrong. gh Nn, It may eafily be difengaged by a fingle diftillation from almotft all its extractive matter; fee VINEGAR (DISTILLED); but it cannot fo eafily be deprived of its fuperabundant - water. If vinegar be diftilled with intention to concentrate it; as vitriolic acid is, the moft watery and leat acid part would always rife firft; but the operation would fucceed very imperfectly, becaufe this acid is almoft as volatile as water. To procure the concentration of vinegar, other expedients muft be ufed. Chemifts have difcovered feveral which fucceed well. For inftance, by combining this acid with fixed matters, fuch as fixed alkalis and metals, and afterwards fubjecting to diftillation the falts refulting from fuch combinations, a very concentrated acid of vinegar is obtained, called, Radical Vinegar. See upon this Jubject ‘TERRA FoLiATA TARTARI, SALT of LEAD, CrYSTALS of VERDIGRISE, and VINEGAR (RApIcAL). We proceed ere to defcribe another method of concentrating vinegar, by which indeed it cannot be fo much dephlegmated as by the preceding methods, but it is much more fimple, and has fome' peculiar advantages. The method is affected by congelation, or freezing. : Stahl feems to be the firft who employed this method. Since which time Mr. Geoffroy has made many experi- ments on this {ubject, a relation of which is to be found in the Memoirs of the Academy for the year 1739. ‘As acids refift congelation much more than water, if vinegar be expofed to a cold fufficient to fink the mercury of Mr, Reaumur’s thermometer eight or ten degrees below the figure 0, a confiderable quantity of ice will be fofmed. is CONDENSATION This ice, being feparated from the. reft of the unfrozeh liquor, confifts of fcarcely any thing but pure water; and the unfrozen liquor is a much ftronger vinegar. = By expo- fing again this vinegar to another and ftrenger froft, more ice is formed in it, lefs Ha: d than the fitft ice, and {ome- what refembling fnow, becaufe it contains a certiin quan- tity of unfrozen acid ; arid may therefore be fet afide for the extrattion of this acid. The acid remaining after the fecond congelation is greatly ftronger. This concentra- tion of vinegar may be much encreafed by repeating the congelation with greater cold. Mr. Geoffroy relates in the quoted memoir, that vinegar which has been already concentrated by frofts of preceding years, and eight pints of which had been reduced to two pints and 3 half by the froft of January 29, 1739, was at length fo much concen- trated, that two drams of this vinegar, the faturation of which before thefe concentrations would have required fix faing of falt of tartar, did now require forty-four grains or that purpofe. : Stahl affures us, that wine may be well concentrated ‘by the fame method. He fays, that he expofed to froft different kinds of wine, and that he had procured by this means two thirds, or three quarters of pure phlegm. Wines thus concentrated had a thick confiftence, were very ftrong, and were preferved without change many ears, in places, where the free accefs of air, alternately i and cold, according to the feafons, would have foured or fpoiled any other wine in a few weeks. The general opinion that wines are fpoiled and entirely weakened by froft proceeds undoubtedly from the ice not being taken off, but left to mix again with the wine when it thaws. Perhaps alfo fome delicate wines are confiderably altered by froft. Wallerius fays, that, in the northern countries, cold is- fuccefsfully ufed to’ concentrate fea-water, and to appro- .Xximate the particles of falt, b ' feparating the ice as foon as it is formed, and which is ittle elfe but pure water. We might be induced to believe that the mineral acids might be concentrated by congelation, as indeed they might be, if they were mixed with a very great quantity of water : but their adhefion to water is fo ftrong, that they cdfinGt be much concentrated by this method. : DIY CONDENSA 11 ON. By the condenfation of a ‘body we ought to underftand the approximation of its in tégrant parts, fo that it occupies a fmaller fpace; snd. that its fpecific gravity i§ augmented, without the lof of any R 2 hetero» et sn Ae 1 PRO - a ————————— 3 . CTOP. PER heterogeneous matter. For inftance, air, forced by com- preflion to confine itfelf within a narrower fpace, is to be confidered as condenfed. CONE. (uz) CONTRAYERVA. (x) COPAL. COPPER. Copper, called alfo by chemifts Venus, is an imperfect metal of a red thining color. It is harder, more elaftic and fonorous, but alittle lefs duile than filver. It is neverthelefs confiderably duétile, and nay be drawn into wire as fine as hair, or beaten into leaves almoft as thin -as thofe of filver. (#) Cone (MerTiNg). This is a hollow cone formed of copper or of brafs, with a handle, and with a flat bottom adjoin- ing to the apex of the cone, upon which it is intended to reft. Its ufe is to receive a mafs of one or more metals melted together and poured into it. This mafs when cold may be eafily fhook out of the cone, from the figure of the veflel. Alfo if a melted mafs, confifting of two or more metals, or other fubftances not combin- ed together, be poured into this veflel, the conical figure facilitates the feparation of thefe fubftances according to their refpetive den- fities. The cone ought to be well heated before the melted mafs 1s posted into it, that no moifture may be contained, by which a dangerous explofion might be occafioned. It ought alfo to be greafed internally with tallow, to prevent the adhefion of the fluid matter. : (x) ConTraYERVA. The leaves of this plant are faid to af- ford a poifon employed by Indians for poifoning arrows, to which - poifon the root of the faid plant is faid to be an antidote. From an ounce of the root Neuman extracted, with water, three drams and half a fcruple; and from the fame quantity, with fpirit of wine, five fcruples and two grains. (1) Cora, improperly called gum copal, is a hard, fhining, “ tranfparent, citron-colored, odoriferous, ‘concrete juice of an American tree, but which has neither the folubility in water common to gams, nor the folubility in fpirit of wine common to refins, at leaft in any confiderable degree. By thefe properties it + refembles amber, It may be diffolved by digeftion in linfeed oil, with a heat very little lefs than fufficient to boil or decompofe the oil, Fhis folution, diluted with {pirit of" turpentine, . forms a beautiful tranfparent varnith, which, when properly applied, and flowly dried, is very hard and very durable. This varnifh is applied to fnuff-boxes, tea-boards, and other dtenfils, It pre- “derves and gives luftre to paintings, and greatly reftores the de- eayed colors of old pitures by filling up the cracks, and render- ing the furfaces capable of refletting light more uniformly. The COPPER The tenacity of the parts of this metal is very confider- able, face a eopper pits the diameter of which is a tenth art of an inch, is capable of fupporting a weizht of 264 A without breaking. pporant X ! 4 Copper weighed by the hydroftatical balance lofes in water - about an eight or a ninth part of its weight (z).. It has a very fingular and difagreeable fmell and tafte. It cannot be fufed without a violent degree of heat fufficient to make it white. : Copper, being an imperfe&t metal, may be burnt, de- ftroyed, and calcined by the united ation of fire and air ; for which reafon its quantity is always diminifhed by melt- ing it without covering its furface. : hen it is expofed to a great fire with free accefs of air, it fmokes, lofes part of its weight, and communicates to flame beautiful green and blue colors. It refifts more than any other imperfe&@ metal the a&ion of fire before it fuffers any confiderable alteration. When a clean and polifhed copper plate is gently and gradually heated, its furface is covered with. all the colors of the rainbow. = This appearance proceeds from the develope- ment, and the different flates of the phlogiffon of the metal. (a) When this metal is expofed to red heat with conta® of air, its furface becomes quickly tarnifhed, and.its metallic luftre is changed into a dark and earthy appearance; and. if this heat be continued during a certain time, the furface of the metal is burnt and deftroyed ; fo that when it cools, it is found to have no longer any adhefion with the un. calcined copper, but to be feparated in fcales from the (x) The fpecific gravity of European copper is to that of water as 8843, and of Japanefe copper as gooo to 1000. (a) All calcinable metals are fubje@ to receive thefe colors or irifes by heat ; and from the color of any part of a piece of metal we may difcover what degree of heat has been applied to that part, as the fame degree of heat always gives the fame color to the fame metal : hence artifts, by obferving the colors acquired by fteel ex- pofed to fire, are enabled to apply to pieces of that metal the pre- cife degree of heat which they have found by experience to produce the required hardnefs, in the operation of tempering fteel. The irifes, or different colors given to different parts of one piece of metal, are occafioned by the heat being unequally applied. Thefe colors are produced by a more or lefs perfeé&t calcination of the furface of the metal expofed to heat, R 3 difference €C OPPER difference of the contradtion, occafioncd by: cooling, upan the uncalcined copper, and upon its burnt furface. When this furface is feparated, the copper beneath it feems clean and fhining; but it will foon fuffer the fame change as the farmér, if it be again heated; and thus a piece of copper may be entirely reduced to fcales no longez pofiefled of brilliancy, duétility, or other metallic pro- perties, and which are called burnt copper. This calcined copper is lefs fufible than copper in its metallic ftate :’ when expofed toa great fire, but avery {mall quantity of copper is obtained from it; the reft of it is changed into a dark and opake vitrified fcoria; except the fcales have been mixed with fome matter capable of reftoring to them phlogifton ; in which latter cafe a quantity of mal- leable copper is obtained nearly equal to that of the fcales employed. Sez REDucTiON of METALS, ‘Thefe copper [cales, which are at firft but imperfeétly calcined, may be entirely deprived of phlogifton and of theix metallic properties by a fecond calcination’ under a muffle continued fufficiently long. ; : : Copper is alfo affeted by the combined adtion of air and water: hence its furface is apt to tarnifh, and even to .be covered with a green ruft, called verdegrife. | This ruft is copper partly décompofed, and deprived of part of its inflammable principle; for it cannot be melted into copper without much lofs, excepting its phlogifton be reflored by fome redu@ive flux. Thefe are alterations to which all the imperfe@ metals are fubject. See MgraLs (ImpERFECT). tei : : This metal is eafily foluble by all acids, and its folutions Bre green or blue. (5) j es 2 Vitriolic acid, although the firongeft of ali, diffolves copper more difficultly En any other: it muft be con- centrated and affifted by confiderable heat and time to dif- folve this metal. From this. folution refults a neutral falt, which forms beautiful blue cryftals, called blue witripl, or vitriol of copper. See thefe words, Nitrous acid diffolves copper very ‘quickly with violence and effervefcence ; and during the folution it takes from the, (5) Solutions of copper in vitriolic acid, vegetable acid, oil, or water, are green ; that in marine acid is at firft brown or, yel- low, and becomes afterwards, green ; and that in aqua fortis is, of a bluifh-green color : volatile or fixed alkalis make the folu- tions of copper in acids blue : a {olution of copper in volatile al- kali, expofed to air, 1s blue, metal COPPER metal part of its phlogifton. The nitre formed by this folution is a very deliquefcent falt. The falts formed by marine acid or by aqua regia with copper are alfo very deli- quefcent. : : Vegetable acids, and particularly thofe of wine and of vinegar, may be eafily united with copper. The former acid forms with it the verdegrife ufed in painting (See VER- DEGRISE) ; and the fecond, when faturated, forms the falt called cryflals of verdegrife, or cryfial of Venus. See Cry- STALS of VERDEGRISE: All acids united with copper may be feparated from it without any intermediate fubftance, ‘and! merely by firei Calcareous earths, fixed and volatile alkalis, feparate copper from any acid, and precipitate it in form of 2 beau- tiful green powder. The color -of thofe precipitates or copper is caufed by a portion of the falts which remain united with them. As the metal thus diffolved and pre- cipitated has loft part of its phlogifton, particularly when it has been diffolved by vitriolic and nitrous acids, thefe precipitates of copper cannot be melted: into malleable copper without addition of phlogifton: but if they be melted with glafles, or vitrefcible matters, and the fire be properly managed, they communicate their colors to thefe - {fubftances : hence they may be applied’ to imitate precious ftones of a green color, or nearly green, as the emerald, and beryl or aqua marina, and for feveral thades of painting upon pottery and: porcelain. Some metallic matters, which have a ftronger affinity than copper: has to acids, are therefore capable of precipi- tating this metal from its feveral folutions. Iron particu- larly has this property ; for which reafon, if it be added to a faturated folution of copper in an acid, it will be attacked and diffolved by this acid, and it will precipitate the copper; and thus the folution of copper is'changed into a folution of iron. While this happens, a remarkable phenomenon appears: the copper thus precipitated is in its metallic ftate . and brilliancy, This effe, which feems to be general whenever a- metallic matter is feparated from an acid by means of another metallic matter, can only. happen becaufe the precipitating metal feparates entirely and exactly all the acid from the precipitated metal, which earths and alkalis feem incapable of doing; and becaule the precipitating metal fupplies enough of phlogifton to the acid, to prevent the acid from retaining the phlogifton of the precipitated metal, which earths and alkalis are alfo incapable of doing. R 4 However COPPER However that be, this precipitation of co r in ite metallic fiate, by the A of iron, Trib of Jmpofing upon, ‘and aétually has impofed upon perfons ignorant of chemiftry ; who, perceiving that a piece of iron, dipt into a liquor in which they fufpected no copper, be- came covered over with copper, imagined that this liquor had the property of changing iron into copper. : This property which iron has of feparating copper from acids has been applied to ufe, In England, the water in a copper mine is impregnated with a great quantity of blue vitriol, and from which much copper is extracted by means of ‘iron immerfed in it. In Germany fome copper ‘ores are fo pyritous, that they cannot be advantageoufly treated by ordinary fufions, but are reduced into vitriol, and by means of the iron which js put into the lixivium of this vitriol, called cement water, a confiderable quantity of copper Is obtained, which would otherwife be loft. See OrEs PyrITES, and ViTrIiOLS, > Copper produces, with refpe to mercury and filver dif- folved in acids, the fame effects which itfolf fuffers from on ; in is it feparises thefe metals fo exaétly from the acids with which they are unit i their metallic luftre, y Sie fey ee vin his property of copper is employed to obtain filver dif- folved by fpirit of nitre in the operation of parting. ‘This tilver is generally very pure, f a very clean plate of copper be immerfed in a folution of mercury, particularly if this folution have an excefs of acid, it will be very foon covered over with mercury, which adheres to it, and which, when wiped and wathed, ‘makes a very white and brilliant filvering. This alfo is one of the experiments which exhibit an appearance of tranfmutation capable of aftonithing thofe who are gnorant of chemiftry. Every dav credulous perfons are deceived by tricks. no better than this, No metal is more foluble than copper. It is ated upon by almoft all faline and metallic fubftances, and probably for this reafon ancient chemifts have called jt Venus, con- fidering it as proftituted to all fubftances. Fixed and volatile alkalis eafily diffolve copper, either directly, or fill better if it has been previoufly diffolved in acids, See ALkALIs (FIXED and VoraTiLE), Moft neutral falts corrode its furface, and reduce it into verdegrife, The fame effe@ is produced by all oils and fat matters, from the latent acid which they contain, Sulphur COPPER Sulphur has confiderable action upon copper, and even has a greater affinity with it than with any other metal excepting iron : hence copper may be feparated from almoft all metals by means of {ulphur, which alfo renders it thuch more fufible. Copper is formed into a mineral or pyritous ftate by union with fulphur; and if this compound be expofed to fire, fo that the fulphur fhall be burnt, its acid will act upon the copper, and reduce it to blue vitriol. i Copper may be eafily united with all metals and femi- metals, and with them forms allays ; of which fe the detail at the articles ALLAY, Bronze, ToMBAC, and SIMILOR. As this metal is combuftible, it may be feparated from the perfect metals by calcination, which is accelerated by means ‘of lead, as in refining ; or by nitre, which generally, much accelerates the calcination of all combuftible bodies 3 fo that by repeated projections of nitre upon melted gold and filver allayed with copper, the nitre burns the phlogif- ton of the copper, and reduces this metal into a fcoria which floats upon its furface : but the nitre muft be added gradually, and but a little at a time, particularly if much copper be in the allay, becaufe the detonation which it occafions is fufficient to diffipate fome of the perfe& metals. See NRE, The affinities of copper, according to Mr. Geoffroy, are mercury and lapis calaminaris, or rather zinc ; and accord- ing to Mr. Gellert, gold and filver. (¢) COPPER (WHITE). White copper is an allay of copper, zinc, and arfenic, in certain proportions, and is white as filver. The precife proportions cannot be eafily determined, and the allay cannot without difficulty be made, becaufe of the volatility of the two femi-metals. Neverthelefs, a very beautiful and filver-like white copper is made by fome artifts, who carefully conceal their me- thod of ‘preparation. he As this allay is not much ufed, from its very noxious quality, chemifts have not confidered it; otherwife any of them who knew the management of metals might probably difcover it. (¢) Wallerius fays, that if a mixture of calx of copper and fal ammoniac be expofed during a certain time to air, from that mafs, by diftillation with foap, mercury may be obtained ; whence he infers, that either mercury is a component principle of copper, or that at leaft fome part of the copper is convertible into it. ? The CREAM i lid virtues of copper are treated of under the CORAL. (d) CORK. (¢) : SORE (FOSSIL). ¢p CREAM. This name is applicable to all fubftances which feparate from a liquor, and colle upon it : but it is particularly i to the following diy yeeces CREAM of LIME. The cream of lime is that moft at- kenuated part of quicklime, and moft approaching to a faline flate, which. is diffolved: by water with, which quicklime is flaked, or even in which flaked lime is boiled, ‘This matter feparates from. lime-water by eryftallization during the eva. oration. of the water ; and as water only evaporates at its urface, this earthy cryftallization is ally formed there. It forms a femi-tranfparent pellicle, which becomes thicker and thicker till it feparates into. pieces, and falls to the bot- tom by its weight in form of fcales. The cream of lime has the fame properties as flaked lime has. See Quick-LiME. (g CREAR (d), Cara and CorarLine are hells of marine animals of the polypus kind, and poflefs the fame chemical properties as the frefh fhells of oyfters.and other fhell-fith, that is, they are calcareous earths impregnated with fome animal principles. See EarThs (CaL- CA®tous). From fixteen ounces of coral, Neaman obtained by diftillation fix {cruples of a volatile, alkaline, oily fpirit, two or three grains of empyreumatic oil, and a refiduum containing five fishes ud a half of fixed falt, probably lea-falt. The quan- “€s.ol thele: component parts were found to v i the frefhnefs of To, ey : R09 Suconting to . (e) Corxk is the bark of a tree of the oak kind, which, grows in. the fouthern parts of Europe, From an ounce of cork Neu- man extralted, by boiling in water, two fcruples ; and from the fame quantity he obtained, by digeflion in {pirit of wine, two fcruples and two grains, i 25 : (7) Cork (Fossiy), Suber montanum, This name is given to a fone which 1s a fpecies of amianthus, confifting of flexible fibres loofely. interwoven, and fomewhat refembling vegetable cork. This is the lighteft of all flones. By fire it is Rufible, and forms a black glafs. It poffefles the general properties of amianthus, Sez AMiAnTRUS. (£): Cream of lime is very different from flaked quick-lime. The latter fubftance is calcareous earth deprived of its gas, or fixable. air, and combined with water : it'is:cauftic, foluble in water, and poflefles all the properties of. quick-lime, from which it differs only in containing a quantity of water, - Cream of lime is ; CROCUS P CREAM of MILK. This is the moft oily part of milk ; which being naturally, only mixed, and not diffolved in milk, and being fpecifically lighter than the other parts, feparates from them by reft, and collects on the furface of the milk, from which it is generally fkimmed to complete the difengagement of the oily from the cafeous and ferous arts, that is, to make it into butter. See BUTTER and ILK. ~ Cream of milk, which is generally called imply cream, js not only an agreeable aliment when recent, but is alfa ufeful in medicine as a lenient, when applied to tetters and erifipelas accompanied with pain, and proceeding from an acrid humor, CREAM TARTAR. Cream of tartar is, pro= perly fpeaking, that part of the concrete acid of tartar which. cryftallizes firft, forming a pellicle on the fyrface of water in which tartar has been boiled, with intention to purify it, and to feparate from it its moft faline part. Thus this fubftance called cream, from its manner of formation, does not eflentially differ from the cryftals of tartar which are formed in the liquor ; and thefe cryftals are according ly, as well as the faline pellicle, generally called cream of tartar, thefe two matters being confounded together by one name, from which no inconvenience refults. S¢¢ TARTAR, CRIMSON. (4) ” j CROCUS. This Latin word, fignifying faffron, has been applied. as a name to earths of certain metals, which in color fomewhat refemble faffron : fuch particularly are the earths of iron and of copper, each of which is there- fore called eracys, the: firfk being the crocus of mars or of aon, and the fecond the crocys of copper: but the word faffron is. more commonly employed, and particularly ap- plied to the earth of iron. 8c SAFFRON. iy calcareops earth, which having been deprived of its gas by cal- cination, and diffolved by water, is, by expofure to air, again combined, with gas; by which it is rendered mild, cryftallizable, unfolyble in water, and reftored to its original ftate before cal cination. See. Gas. (4) Crimsoy. A crimfon color may be given to filks and woollen cloths by cochineal. Se. Cocuinear. A lefs durable erimfon may be given by Brazil wood. For the color called by - dyers demi crimfon, the root of madder is mixed with cochineal, See Rep and Dying, CRUCIBLE, CRYSTAL CRUCIBLE. (i) 4,00) CRYSTAL. Cryftal, called alfo rock-cryflal, or natu- ral cryflal, is a hard, tranfparent fone, of the figure of a prifm with fix faces, which is terminated at each of its ex- tremities by hexagonal pyramids: : . The moft beautiful rock-cryftal is that which is perfeét- ly clear, white, and tranfparent. It is frequently cut; and luftres, vafes, and toys are made of it, as of other beautiful ftones. Rock-cryftals, like the precious ftones, are of all colors ; and they receive their color, as the pre- cious ftones do, from metallic and phlogiftic fubftances. Some of them are brown, and almoft black; thefe may be rendered white and tranfparent, by making them red- hot, which muft be done very gently and gradually, to prevent their cracking, which they are very apt to do as well as other vitrifiable ftones. Soe EarTH (VITRIFI- ABLE. (4) CRYSTAL (7) Sec PorTERY. : ¥ (#) Cryffal, rock-cryfal, or quartz-cryflal, is a tranlparemt ftone of the clafs of earths called by fome filiceous, and by others vitrifiable. Its form is that of an hexagonal prifm, one or both ends of which are terminated by hexagonal pyramids. Some of them confift of thefe two pyramids joined together at their bafes, without any prifm interpofed. Cryftal is frequently found ad- hering to quartz; and, according to Cronftedt, it is nothing but quartz, which he aifirms always affumes this hexagonal form, when its accretion or cryftallization has not been interrupted. Cryftals are either colorlefs, or colored. 'Thofe which are red are called falfe rubies ; the violet colored, Salle amethyfis, or, ac- cording to Cronftedt, the true amethyfis ; the yellowith-red, fal/e byacinths ; the blue, Jalfe faphirs; yellow, falfe topazes; the greenith-yellow, fale chryfolites ; the green, falje emeralds ; the fea- green, falfe beryls. Some cryfals are dutky, brown, or blackifh, t fill tranfparent. Cryftals poflefs the general properties of the earths called vitrifiable. “See EArTHS (VitririapLe). Color- lefs cryftals refift the moft violent and long continued fires, See Mr.D’ArceT upon Vitrification, in the Memoirs of the Acade- my of Sciences, for 1776. Molt of the colored cryftals are fufible ~ by violent fire, They probably receive this fufibility, as well as their color, from metallic fubftances. = Colorlefs cryftals may be, tinged with various colors, fo as to imitate precious ftones, For this purpofe, Neri, in his Zr of making Glafs, direéts that pieces of clear cryftal thould be laid upon a mixture of four parts of orpi- ment, four parts of crude antimony, and one part of fal ammo- niac, placed in a crucible, to which another crucible inverted is well CRYSTAL CRYSTAL (FACTITIOUS). The word cryftal has been applied to glafles produced by art, which from their tranfparency and whitenefs imitate rock-cryftal. In fact, fome are made as beautiful as the fineft rock-cryftals, but not nearly fo hard. The heat of ordinary vitrification feems incapable of producing glafs as hard as rock-cryffal ; nor do our crucibles feem capable of fuftaining the requi- fite heat, if it could be raifed. See the method of making cryflal-glafs at the words GLAss and VITRIFICATION. CRYSTAL (MINERAL). Mineral cryftal, called alfo Salt of Prunella, is melted nitre detonated with a little fulphur, and caft into form of tablets. Nitre is one of the neutral falts which contains the leaft ‘water in its cryftallization, or which lofes the leaft water by a true fufion, and is alfo one of the moft fufible falts. To make mineral cryftal, very pure nitre muft be put into a clean crucible, and quickly fufed, taking care that no afhes or coal fall in. When the nitre is fuled, it is to be detonated with fulphur, in the proportion of a dram of the latter to a pound of the former. It is then to be poured well luted : the crucibles are to be placed in a furnace, and fur- rounded with charcoal : after heat has been gradually applied till the crucibles become red, and the fire extinguifhed, the upper pieces of cryftal will have acquired a fine golden color, refembling opals, and variegated with beautiful {pots : the lower pieces of cryftal will have acquired a fine color, refembling that of the fkins of vipers. He gives another procefs, in which he dire&s the ce- menting mixture to be compofed of two parts of yellow orpiment, two parts of white arfenic, one part of crude antimony, and one part of fal ammoniac. He direéts alfo, that no bellows or ftrong current of air fhould be applied to the fire, by which he fays, that the cryftals are apt to be cracked, probably by making the heat too intenfe, and that the crucibles fhould not be opened till they have been gradually cooled. Cryftals thus treated refemble rubies, opals, agates, turquois, marbles, chryfolites. Mr. Pott fays, that he found the color of fome cryftals much improved by ‘repeating the operation. Baptifta Porta direts, that cryftals fhould be colored by keeping them immerfed during four or five hours in a’ melted mixture o fulphur, crude antimony, orpiment, arfenic, and tutty. In thefe operations, the cryftals feem to im- bibe fome of the vapors of the metallic fubftances, The chief difficulties feem to be to prevent the cracks to which the cryflals are very fubje@ by this treatment, and to procure a fufficient pee JMetration. Probably both thefe purpofes might be ‘effected by a very frit attention to the gradual application, and ta the main- tenance of a due degtee of heat. into CRYSTALLIZATION into a copper, or rather 4 filver bafon, in which it is to be agitated while yet fluid, that it may fix in form of cakes or tablets. © ~~ No other effet is produced upon the nitre by the {mall quantity of fulphur with which it is detonated, “than to in- troduce into it a proportionable quantity of vitriolated tartar, called Sal Polychrejt of Glaffer. In all other refpeéts, chemical and medicinal, mineral cryftal is nitre, and may be given like this, from four grains'to ten or twelve; in a ~ quart of proper drink., It is cooling, fedative, aperitive and diuretic. This preparation then feems ufelefs, fince the fame intentions may be better accomplithed by well purified nitre. See N1TRE. CRYSTALLIZATION. This word is fometimes employed to fignify fubftances which are cryftallized, or whofe parts are fo arranged that they form regular figures. In this fenfe, we fay flony cryflallizations, pyritous eryflalliza- ions, &ec. ; ; CRYSTALLIZATION of SALTS and of other Subfiances. If the word cryftallization were to be confined to its moft proper fenfe, as it feems to have been former- ly, it could only be applied to operations by which certain fubftances are difpofed to pafs from a fluid to a folid fate by the union of their parts, which fo arrange them- felves that they form tranfparent and regularly figured’ - mafles, like native cryftal; from which refemblance the word cryflallization has evidently been taken. But modern chemifts and naturalifts have much extend- ed this expreflion, and it now fignifies a regular arrange- ment of the parts of any body which js. capable of it, whether the mafles fo arranged be tranfparent or .not. ‘Thus opake ftones, pyrites, and minerals, when regularly formed, are faid to be cryftallized, as well as tranfparent ftones and falts, I The opicity and- tranfpatency of - fubftances: are. juftly difregarded in confidering whether ‘they be cryftallized or fot; for thefe qualities are perfectly indifférelit’ to ‘the re- gular arrangement of the infegrant parts, of ‘fubftances, which is the effential object of cryftalfization: “~:~ This being eftablifhed, cryftallization oprght to be defined an operation by which’ the ingegtantopafts of a boly, fe- parated from each other by the interpofition of a fluid, are difpofed to unite again nr to form folid, regular, and uni- mafles, Ts CRYSTALLIZATION To underftand as much as we can of the mechanifim cryftallization, we muft rémark, mia % 1. That the integrant parts of all bodies have a tendency to each other, by which they approach, unite, and adhere together, when not prevented by an obftacle. : 2. That in fimple, or little-compounded bodies, this ten- dency of integrant parts is more obvious and fenfible than in others more compounded : hence the former are much more difpofed to cryftallize. : : 3 That although we do not know the figure of the primitive integrant molecules of any body, we cannot doubt but that the primitive integrant molecules of every Gifsche body have a conftantly uniform and peculiar gure. 4. That thefe integrant parts cannot have an equal tendency to unite indifcriminately by any of their fides, but by fome preferably to others, excepting all the fides of an integrant part of a body be equal and fimilar ; and probably the fides, by which they tend to unite, are thofe by which they can touch moft extenfively and immediately. he moft general phenomena of cryftallization may be conceived in the following manner. : Leta body be fuppofed to have its integrant parts fepa= rated from each other by fome fluid. If a part of this fluid be taken away, thefe integrant parts will approach toge- ther ; and as the quantity of intervening fluid diminifhes, they will at laft touch and unite. They may alfo unite, when they come fo near to each other that their mutual tendenc thall be capable to overcome the diftance betwixt them. If, befides, they have time and liberty to unite with each other by the fides moft difpofed to this union, they will form maffes of a figure conftantly uniform and fimilar. For the fame reafon, when the interpofed fluid is hattily taken away, fo that the integrant parts fhall be approxi- _ mated, and be brought into contact before they have taken the pofition of their natural tendency, then they will join confufedly by fuch fides as chance prefents to them ; they will in fuch circumftances form folid mafles, whofe figures will not be determinate, but irregular and various. In every cryfallization all that we have defcribed may be obferved, If eryfallization be taken in the general fenfe we have gIVEN to it, ice is a true cryftallization. Water, for in- ftance, is to be confidered 2s a body whofe integrant parts are feparated from each o:her by the interpofition of the 3 mater CRYSTALLIZATION matter of fire. Melted metals are alfo to be. confidered in the fame manner. The fluidity of thefe bodies is to be at- tributed to this matter of fire, with which thefe bodies are penetrated, When therefore thefe liquefied bodies cool, which can only ‘be by taking away this igrieous matter that penetrates them ; if the approximation of the in- tegrant parts, which is a neceflary confequence of this cool- ing, be made fo flowly that they fhall have time and liber- ty to unite by the fides moft difpofed to this union, they will always form mafles of a conftant and fimilaf figure. ‘Thus when water freezes flowly, and is not agitated by ' any motion which can difturb the order in which the in- tegrant parts tend to unite, it forms regular cryftals of ice, and always of the fame form. Thefe cryftals which may be called cryftals of water, are long, needle-like mafles, flattened on ‘one fide, joined -together in fuch a manner that the fmaller are inferted into the fides of the greater; and thus thefe compound cryftals have the appearance of feathers, or of leaves of trees. The moft remarkable circumftance attending this cryf- tallization is, that the angle formed by the infertion of the fmaller needles into the fides of the larger ones is al- ways of the fame width, that is, fixty degrees. However, it is fometimes double, that is, 120 degrees ; but it is con- ftantly one of thefe two angles, and it is to be remembered that thefe angles are complements to each other, that is, they are together equal to two right angles. We are obliged to Mr. Mairan for thefe fine obfervations, which he has given at full length in an excellent differtation on ice. Metal, fulphur, and feveral other bodies not much com- pounded, which fix and become folid after fufion, aflume always a regular arrangement whenever they are {lowly enough cooled for that purpofe. The ftar of the regulus of antimony has been long obferved with wonder. Alche- mifts, who faw wonders in all their operations, confidered this ftar as fomething myfterious 'and fignificant ; but the wonder ceafed when the caufe of it was inveftigated by fo good a philofopher as Mr. Reaumur, and difcovered to he the tendency which the integrant parts of the regulus of antimony have to arrange themfelves in an uniform man. ner; for this arrangement always happens, when the regu- lus of antimony has been well fufed, and flowly cooled, Mr. Macquer and Mr. Beaumé having fufed filver with great heat, and afterwards very flowly cooled it, Shred Z that CRYSTALLIZATION that this metal alfo arranged itfelf in a regular manner. Mr. Beaumé obferved the fame effect upon applying to all the other metals and femi-metals the fame treatment, Every metallic fubftance was found to have its peculiar form, which Mr. Beaumé propofes to determine. What we have faid concerning bodies, which being fufed by fire, are cryftallized when they become folid by cold, may alfo be applied to all thofe whofe integrant parts {wim feparately from ‘each other in a fluid fuch as water, Thus all kinds of earths, and of metallic and mirieral matters, which are found in that ftate,. may be cryftallized by taking away fome of the watery fluid which feparates their integrant parts. A flow evaporation of the water ~ which contains thefe fubftances allows their parts to ap= proximate and to unite together by the moft fuitable fides, and to form mafles of a determinate and conftant figure, In this manner are formed the cryftallizations of precious ftones, of rock cryftal, of fpars, of certain ftala&tites, and of all flony bodies found fo frequently well cryftallized. The regular forms of moft pyrites, of many ores and me- tallic minerals, and even of fome pure metals, fuch as gold, filver, copper, which ire found regularly arranged and ramified, ought to be attributed to the fame mechanifm, that is, to the flow feparation of their integrant parts from the water in which they are fufpended. But of all the fubftances thus fufceptible of cryftallizing by their feparation from water, falts are moft difpofed to ity and afford the beft examples of cryftallization ; becaufe all faline fubftances being eflentially foluble in water, are liquefied by this fluid in 2 much greater quantity than the bodies we ‘have mentioned, awhich, properly {peaking, are only mifcible with water. "This property which falts have of being feluble by water muft depend on a certain affinity or adhefion of their in- tegrant parts to thofe of water 3 and from this adhefion we can deduce the phenomena peculiar to the cryftallization of falts, and the differences obfervable betwixt the cryftal- lization ‘of thefe, and that of other fubftances to which water has not the fame affinity. We fhall relate what is moft neceffary to be known concerning the cryftallization of falts, an object of great importance in chemiftry. j + The cryftailization of a falt diffolved in water may be procured, as evidently appears from what we have faid, by taking away the diffolving water : ‘and as moft falts are lefs volatile than water, and may even be confidered com- ot. 1. S paratively CRYSTALLIZATION paratively as fixed fubftances, this fubftrattion may be com. modioufly. made by the evaporation of a fufficient quantity - of water. The parts of the falt, being fufficiently ap- proximated by this evaporation, will’ unite together and form ¢ryftals, as we have already explained concerning other fubftances. But as the faline parts adhere to thofe of the water, this circumftance occafions an effential difs ference in the cryftallization ; which is, that the falt when cryftallizing, does not feparate itfelf from all the water with which it was united in folution, but retains fome part of it with fome force ; and this portion of water adhering to, and even combined with the parts of falt, makes with it one whole or entire body; whence faline cryftals are compounded of cryftallized falt, and of water which makes part of thefe cryftals. This water is called by chemifts the water of cryflallization. As this water of cryftallization is fuperabundant to the eflence of the cryftallized falt, it may be taken from it by evaporation with a certain degree of heat, without any change produced upon the eflential properties of the falt; fo that it may be again diffolved and cryftallized as at firft. But we muft obferve, that the water of cryftallization can- not be taken from any falt without deftroying the form, or at leaft the confiftence, or the tranfparency of the cryftals; and when the falt is to be re-diflolved and re-cryftallized, it retains in this fecond cryftallization the fame quantity of water precifely as it had in the firft. Hence we ought to conclude that this water of cryftal- lization is not eflential to a falt, as a falt, but that it is effential to a falt as being cryftallized ; fince to it the faline cryftals owe their form, tranfparency, and even the cohe- fion of their parts. ‘The quantity of water of cryftallization varies much in different falts. Some of thefe, as alum, Glauber’s fat, and martial vitriol, contain about half their weight of water ; and others, as nitre and fea-falt, contain but a fmall quantity. Selenites contains an almoft infenfible quan- tity of water. This difference feems to depend on the ftate of the acid in thefe falts; and in general the more firmly an acid is combined with its bafis, the lefs water it retains in cryftallization. : A very important remark to be made upon this wateh of cryftallization, is, that when the cryftallization is pro- perly managed, this water is perfe&tly pure, and contains no fubftance foreign to the cryftallized falt. To Mr. : Beaumé CRYSTALLIZATION Beaumé we owe this difcovery. By many experiments he was convinced that no neutral falt, with a bafis of fixed alkali, retains in its cryftals either fuperabundant acid or alkali, or any other matter foreign to the neutral fale, al- though even this falt had been cryftallized in a liquor that was acid, alkaline, or impregnated with any other fub- ftance foreign to the falt ; and that if {fometimes thefe hete- rogeneous fubftances are found included in faline cryftals they have no adhefion to them, fince they may be feparat- ed merely by draining upon brown paper, without any change produced upon the cryftals of the falt 3 whereas the water of cryftallization cannot be taken away without a deftrution of the cryftals. The caufe of this phenome- non will eafily appear, when we regolle® that falts retain the water of their cryftallization by the adhefion of thefe falts to water ; and that if a falt be diffolved in water im- pregnated with acid, alkali, or other fubftance foreign or fuperabundant to the falt diffolved, this falt does not adhere either to the fuperabundant acid, or alkali, nor to the other extraneous fubftances, but to the water alone. Evaporation of water, in which falt is diflolved, is not the only method by which the falt can be cryftallized. An- other method which may be ufed with fuccefs, at leaft for the cryftallization of moft falts, is by application of cold to the water fufpending the falt, The reafon of this is as follows, | j _ All falts are foluble in water, but not with equal faci- lity, fome of them requiring much water, and others very little : ‘moft of them are more eafily diffolved, and in greater quantity, by hot than by cold water ; and others with nears ly equa ellity, and in equal quantity by both hot and cold water, This being eftablithed, when boiling water that is, water heated as much as poffible, fufpends in folu- tion all that it can diffolve of thofe falts which are more foluble by hot than by cold water, if this water be cooled the portion of falt which was diffolved merely by the heat of the water, will be colle@ed and cryftallized as faft as the water cools, We may alfo obferve, that when this cool- Ing of the water is very quick, the cryftals it occafions ll, negular, and ill-thaped ; and that the more the coolin : a cri ing 1s produced, the larger and better form- at has been hitherto faid concerning the re taken by certain liquefied matters Foon a omms becoming folid, is entissly applicsble to this kind of cryf- ) 2 tallization CRYSTALLIZATION tallization of falts. This cryftallization is not effected by a fubftra@ion of water but of fire, by which fubftration a condenfation of the faline liquor is produced, and confe- quently a fufficient approximation of the parts of the diffolv- ed falt to difpofe them to unite, and to form cryftals ; and as in this cafe, the fluidity or the folidity of the falt is folely occafioned by the prefence or abfence of the matter of firs, thefe falts diffolved by heat, and cryftallized by cold, may be compared to melted metals, the parts of which are regu- larly arranged by a flow cooling. But with regard to falts we muft obferve, that as their cryftallization is performed in a fluid to which they have an adhefion, they retain the fame quantity of water of cryftallization, whether the ope- ration was performed by cold or by evaporation. Hence we may perceive, that evaporation and cooling are the two principal methods of cryftallizing falts. Some- times it is proper to employ one only of thefe methods, and at other times both together, according to the particu- lar nature of the falt to be treated. If it be one of thofe falts which are better cryftallized by cooling than by eva- poration, fuch as nitre, for inftance, then the former me- thod ought to be ufed ; for nitre cannot be well cryftallized by evaporation alone, becaufe the water which keeps it dif- folved would be reduced almoft to nothing befere the cryf- tallization would begin, and the liquor would be fo con- centrated that the parts of the falt would not arrange themfelves properly. When, therefore, nitre is to be cryftallized, the water is to be evaporated fo far only, that when it cools, cryftals {hall be formed. This degree of evaporation is known by taking a few drops of the hot liquor, and cooling them quickly ; if the evaporation has been fufficient, {mall cryf- tals may be perceived inftantly formed. As the evapora- tion here mentioned does not occafion the cryftallization of the nitre, but is only preparatory to it, this evaporation may be either quick or flow without inconvenience. The liquor may be made to boil as faft as poffible, and the cryftals of nitre will be no lefs perfect, provided that this liquor when fufficiently evaporated be flowly cooled : when it ‘is perfeétly cooled, no more cryftals will be formed in it. It ought then to be poured off, and again evaporated, when by a fecond cooling it will furnifh more cryftals, and this treatment is to be continued to the end. But if well formed cryftals are to be obtained of one of thofe falts which are nearly as foluble in cold as in boil- ing CRYSTALLIZATION ing water, and which confequently cannot be cryftallized by cold, evaporation is the only method to be ufed. Com- mon falt is a proper inftance of this kind. Water impregnated with common falt muft be evaporated to obtain cryftals; and when the liquor contains much more water than is neceflary to the folution of the falt, the evaporation may be carried on as faft as poffible till the cryftallization is ready to begin. This point is known by a thin, faline pellicle, which floats on the furface of the liquor, and feems as if duft had fallen upon it. This pellicle is compofed of the firft portions of falt beginning to cryf- tallize. It is always formed at the furface ; becaufe this falt cryftallizes by evaporation only, and evaporation is only at the furface. - : Mr. Rouelle, in his Memoir concerning the Cryftallization of Sea-falt, fays, that he has obferved, that when the eva- poration has been very flow, and with a heat not much ex- Seeding that of fummer, the cryftals of common falt are formed at the bottom and not at the furface of the liquor. As this appears quite contrary to the manner in which this falt cryftallizes in all other circumftances, have we not reafon to believe, that in this infenfible evaporation the cryftals of fea-falt are formed firft at the furface, as in all other evaporations, but that they cannot be perceived from the extreme fmallnefs of their fize at firft ; and becaufe the heat is too weak to dry their upper furface, and to make them adhere to the air, thefe fmall cryftals fall to the bottom without being perceived, and there become larger by the union of other {mall cryftals, formed and precipi- tated in the fame manner ? _ If the evaporation when brought to the point of cryflal- lization was to be ftopt, and the liquor to be cooled after it has been filtrated, and put into a bottle to prevent fur- ther evaporation from the remaining heat, fcarcely any cryftals would be formed in it, but the {alt would remain diffolved in the water. If, on the contrary, the evapora- tion fhould be hatftily continued, falt would indeed be formed in great quantity; but as its parts would not have | time to aeiange themfelves properly, the cryftals would be fmall and ill-fermed *. The evaporation therefore ought to be ; * Althongh cryftals of fea-falt are generally lefs regular when ormed by a hafty than by a flow evaperatien, this irregularity is, however, lefs fenfible in this falt than in moft others, and its : S 3 cryflals CRYSTALLIZATION be continued, ‘but {lowly : and by this method very beaut. ful cryftals will be obtained, partly in cubes, partly in hollow pyramids formed by cubes +. The rules of cryftallization moft fuited to the nature of each falt muft be obferved, not merely to obtain well. formed cryftals; for if their figure was once determined, the regularity of their cryftallization would be afterwards of no confequence: but the cryftallization of falts relates to an affair of much more importance, which is their purity. We have already faid, that, when a falt is well cryftal- lized, the water of its cryftallization is very pure, and contains none cf the heterogeneous matters which happen- ed to be mixed with the folution of the falt before cryftal- lization. This obfervation may be extended to other falts which may happen to be diflolved in the fame liquor. If then feveral falts be diffolved together, we may almoft al- ways feparate them exactly from each other, by cryftal- lizing each of them according to their charaéter; for amongft the almoft infinite number of falts now known, fcarcely two thow precifely fimilar phenomena in cryftalli- zation. We may, from the example of feparating nitre and common falt, when diflolved together in the fame liquor by cryftallization, thow how fuch feparation may be done cryftals always tend to a cubic form, or at leaft appear compofed of cubes. . From this obfervation we have reafon to believe that the primitive integrant molecules of this falt are cubes: hence we may conceive that as all the fides of this falt are equal and fimilar, from their union regular folids ought to refult, more or lefs ap- proaching to the cubic figure, by whatever fide they may have been nnited. Nete of the Author. + Although in a moderate evaporation a very large quantity of cryftals of common falt is Perea Ir quadrangular, hollow, and inverted pyramids, the cubic figure is neverthelefs the primitive and eflential form of this falt; for thefe pyramids are all compo- fed evidently of cubes. Beiides, they are only formed acciden- tally, by the union of feveral quadrangular prifms compofed of cubes, which are fucceflively applied to the fides of a firlt cube; which being formed at the furface of the liquor, remains fufpend- ed there, by the adhefion of its upper dried furface to the air. As this cube is befides a little funk into the liquor by its weight, fo that the liquer rifes along its fides, it becomes by that means 2 very proper foundation for the formation of this pyramid. This mechanifm is explained at length in Junker’s book, and ina Memoir of Mr, Rouelle concerning the cryftallization of fea-falt, printed in 1745. Note of the Author. : in B CRYSTALLIZATION in general, even when feveral falts happen to be fo ccn- ed. This is certainly one of the fineft and moit ufe- roblems in chemiftry. ; gr us then fuppofe Te nitre and fea-falt, diffolved in the fame liquor, are to be feparated from each other. The method of effeCting this will appeat evidently from con- fidering what we have faid concerning cryftallization ; and this method will be found to confift in employing alternate- ly evaporation and cooling. Firft of all then, the liquor muft be evaporated. If, during the evaporation, a pellicle appears on the furface, and no cryftals of nitre appear ina {mall quantity of the liquor when haftily cooled, then we difcover that common falt is in greater quantity than the nitre. In this cafe the evaporation muft be continued, and the common falt feparated as faft as it is formed, till a {mall quantity of the liquor, when haftily cooled, fhews {mall needle-like cryftals of nitre ; then the liquor is to be left to cool, that the nitre may have an opportunity of cryf- tallizing by cooling ; after which the evaporation is to be refumed that more common falt may be feparated, and to diffipate fo much water, that cryftals of nitre fhall again be formed by cooling. Thus thefe falts may be alternately cryftallized, one by cooling, and the other by cryftalliza- tion, till they are entirely feparated. | If, in the beginning of the operation, the liquor had, upon trial in {mall quantity, given Sry sals of nitre by cooling, before any pellicle had appeared upon its furface, the common falt would then have been known to be in much lefs quantity than the nitre. In this cafe, the nitre would have been cryftallized firft, but always by cooling. ‘The quantity of nitre, which exceeds that of commen falt, having been’ thus feparated, the common falt would then begin to cryftallize in its turn by evaporation. , Several effential remarks are to be made upon this fepa- ration of feveral falts from each other by cryitallization. Firft, although the two falts, the method of feparating which we have given as an example, are the moft capable of fuch a feparation, becaufe fea-falt is one of the falts which are leaft of all to be cryflallized by cooling ; and on the contrary, nitre is one of thofe which are belt cryftal- lized by this method ; neverthelefs, after a firlt cryftalliza- tion of thefe two falts, fuch as we have defcribed, they are not entirely and perfectly feparated from each other : the fea- falt contains fome nitre, and the nitre contains fome portion of fea-falt ; becaufe in cryfiallization one falt always takes wore S 4 with CRYSTALLIZATION with ita fmall portion of another: but when two falts are fo different from cach other in this refpect as thefe two, a per- fet feparation may be eafily made by diflolving each of them feparately in more water, and by proceeding to their cryftal- lization by the fame method. As a new feparation is made by each cryftallization, they may be obtained at laft perfeitly * pure by repeating fufficiently this management. The fecond remark to be made on the feparation of falts by cryftallization is, that this feparation is fo much more difficult and long, in proportion as the falts to be fe- parated are more fimilar to each other in their manners of “cryftallization. For inftance, if two falts are only capable of cryftallizing by evaporation, as fea-falt and vi< triolated tartar, or by cooling, as nitre and Glauber’s falt, they cannot be ever obtained quite pure and feparated from each other by any management : neverthelefs, even in this cafe they may be in great meafure feparated ; firft, becaufe the precife degree of evaporation, or of cold, which is neceflary for the cryftallizing of one falt, is generally fome- what different from that which is requifite’ for the cryftal- lization of another falt; fecondly, becaufe although they fhould refemble each other much in this refpect, fome dif- ferences, which muft- be obfervable in the fize and form of their cryftals when well formed, will furnifh means of making at leat an imperfect feparation, which may be made more perfe&t by repeating this management. , But the feparation of fome falts is attended with fingular and even infuperable difficulties. Such are the falts which have fome ation upon each other, and the parts of which have fome adhefive power together. This action of neutral falts upon each other has been very little obferved : it is, neverthelefs, very fenfible in fome of them; fuch are fal ammoniac and corrofive {ublimate, which not only act as intermediate fubftances to each other, by which they can be - diffolved in greater quantities in water and in fpirit of wine than they can fingly, but which being difiolved together in the fame menftruum, cannot be again cryftallized feparateiy by-any method ; as Mr. Macquer has fhewn in his Memoir concerning Mr. Garay’s Tincture of Mercury, printed in the Collection of the Academy for the year 1755. Some falts have fo great affinity with water, and are fo foluble by this menftruum, that they can fcarcely be cryftaliized. The folution of thefe falts requires to be eva- porated almoft to dryncfs, or to a thick confiftence, and then by cooling they generally form needle-like cryftals applied ‘ longitudinally CRYSTALLIZATION longitudinally or tranfverfely to each other. When they are expofed to the air, they attradt humidity, and refolve into a liquid ftate. Mr. Rouelle was the firft who defcribed, in his Memoir concerning Salts in the year 1744, the cryftallization of deliquefcent falts, fuch as marine falt and nitre with bafes of calcareous earth, of copper, and of iron, terra folata tartari, and the falts formed by the union of the acids of vinegar and of tartar'with iron and withcopper. Al thefe fo difficultly cryftailizable falts may be eafly fepa- rated from falts which maybe readily cryftallized, with which they happen to be mixed ; becaufe the former falts in the evaporations and coolings are always the laft to cryftallize. Two of thefe falts, namely nitre and marine falt, with bafes of calcareous earth, are found mixed with nitre and marine falt with bafes of fixed alkali; both of them in the lixiviums of the manufaCurers of nitre, and the latter in almoft all the waters in which common falt is found to be naturally diffolved : hence, when the proper operations are made to obtain nitre and fea-falt, after all the evaporations and cryfltallizations, a very heavy faline liquor remains from which no cryftals can be procured, called the mother- water. Thefe mother-waters of nitre and of common falt are, then, nothing but thefe falts with earthy bafes almoft pure; and if a cryftallization of them were required, the method defcribed by Mr. Rouelle in the quoted Memoir ought to be practifed. But this is not a matter worthy the attention of the manufacturers, to whom the perfect puri- fication of nitre and of fea-falt, from an adhering portion of the falts with earthy bafis, is of much more importance, as we fhall fee when we fhall treat of thefe falts. Chemifts have given much attention to this fubject, the cryftallization of falts; and particularly Mr. Rouelle has made many interefting refearches concerning it, which may be feen in his Memoir of 1744. But neverthelefs, muc remains yet to be done. The true form of all cryitallizable falts, and the beft methods of cryitallizing them, are not yet determined ; which will not appear furprizing to thofe who underftand this fubjec, and who know that one and the fame falt, although conftantly tending to the {fame form, is neverthelefs capable of difguifing itfelf in many ways, and of taking any different forms, according to the cir- cumftances during cryftallization. The quicknefs or {low- nels of evaporation, the quantity of water evaporated, the more or lefs hafty cooling, and the different degrees of cold applied, the fate of the air and of the liquor with rips: 0 CRYSTALLIZATION to reft or motion, even the form and matter of the veffel in which a falt is cryftallized, are fo many caufes, which, a&ing fucceflively or. together in many different ways, are capable of producing numberlefs varieties in the cryfialliza- ton. Of all the caufes which we have mentioned, capable of varying cryftallizations, the nature of the veflel employed feems to deferve leaft our attention; yet this may produce fome change from the greater or lefs adhefion which the falt may have to the feveral matters of which thefe veflcls are made. For inftance, we can only attribute to the adhe- fion of falts to the fides of the veflels employed the property which moft of them have to branch out in various manners, end to creep along the fides of thefe veflels, particularly when the cryftallization is very {lowly performed, fo con- derably that they frequently go even on the outfide of the veflels. Mr. Beaumé has prevented this phenomenon by hindering the adhefion of the falts to the fides of the veflels, by rubbing thefe fides with fome oil. From what has been faid concerning the ation of neutral falts upon each other, we may conceive, that when fuch falts happen to be mixed together, they muft produce con- fiderable differences in cryftallizing. Many other important obfervations might be made on the cryftallization of certain falts, but they will be better placed under the articles of the feveral falts which they concern. We are obliged alfo to leave to the underftanding and refleétion of our readers to draw from what we have faid many corollaries, the detail of which would be too long. We thall only mention a manner of cryftallizing falts which is different from the methods by evaporation and by cooling, but which confifts alfo in taking away from the falt a por- tion of water which keeps it diffolved. This method of cryftallization is well aftected by adding to a folution of a fait a fufficient quantity of a fubftance which has no action upon that falt, but which has greater affinity than the falt has with the water which keeps it diffolved. Spirit of wine, for inftance, has thefe properties with regard to many falts. Thus: by adding a fufficient quantity of rectified fpirit of wine to a ftrong folution of Glauber’s falt, of vitriclated tartar, or of fea-falt, this fpirit of wine feizing the water neceflary for the folution of the falts, obliges them to cry- ftallize “immediately : but as this cryftallization is very haftily made, and almoft inftantaneoufly, the cryftals are always very fmall and ill-formed, In this refpect they refemble CRYST.ALS refemble the cryftals of falts produced from a liquor which contained too little water to keep them diffolved. This happens, for inftance, when a ftrong folution of alkaline falt is combined with concentrated vitriolic acid, to form vitriolated tartar ; for this falt, which requires much water to keep it diflolved, does not find enough in the liquor, and appears immediately in form of very fmall cryftals like fand. The fame thing may be faid of vitriols of filver and of mercury, of luna cornea, and of other metallic falts of this kind produced by adding vitriolic or marine acids to the white metals diffolved in nitrous acid. Thefe falts appear immediately as precipitates, whenever they do not find water enough in the liquors to diffolve them; and Mr. Rouelle juftly obferves, in his Memoir, that they are not precipitates, but true falts, which not finding water fufficient for their folution, are obliged to be immediately cryftallized, but in cryftals fo fmall, from the rapidity of their cryftallization, that they cannot be known to be cryftals I with the help of a microfcope. Notwithftanding what has been faid concerning the irre- gularity of the cryftals procured by adding a f{ubftance, which feizes the water of the folution of falts, yet if this addition was managed and gradually made, perhaps it might fEodisy very beautiful and very regular cryftals. Mr. eaumé has actually obferved, that when falts were cryftal- lized in acid or alkaline liquors according to their nature, their cryftals were infinitely larger and more regular than they would have been without this circumftance. Vegetable falt, for inftance, and [alt of Saignette, require to be cry- ftallized in an alkaline liquor ; and fedative fo requires an acid liquor, when it is obtained from borax by the interven- tion of an acid, if we defire to have fine cryftals of thefe falts. The caufe of this muft be, that acids or alkalis, having in general more affinity with water than neutral falts have, -diminifh the adhefion of thefe neutral falts with the water of the {olution ; for a too great adhefion of a falt to water may evidently be a great impediment to its cryftalli- zation. See the words SALT, SALTS (NEUTRAL), and the Jeveral [forts of neutral [alts under their refpective names. CRYSTALS. All neutral falts with metallic bafes fufceptible of cryftallization are commonly called by che- mifts Cryffals, when they are actually cryftallized ; and the nan of i metal contained in the {alt 1s added to diftin- guifh it. hus we fay, cryflals of gold, of filver, of copper, of lead, &c, But as HB do Jf Tn contained CRYSTALS contained in each falt, they ought to be difufed. Here we thall only mention two of thefe falts called cryftals; be- caufe they are almoft always diftinguithed by that name, Thefe are the cryfals of filver, and cryflals of verdegrife, or of copper. ; CRYSTALS of SILVER, or LUNAR CRYS- TALS. Cryftals of filver are neutral falts with metallic bafes compofed of nitrous acid faturated with filver. When very pure filver is diffolved by very pure nitrous acid, if the acid be ftrong, cryftals will be formed merely by the cooling of the folution. Thefe cryftals are white, flattened like thin fcales, and not very hard. When the nitrous acid ufed to diflolve the filver is weak, no cryftals are formed ; becaufe the water in the acid is fufficient to keep the newly formed falt diffolved ; but lunar cryftals may eafily be obtained from this dilute folution by evaporating the {uper« abundant water, and letting the liquor cool. Very beautiful and white lunar cryftals may alfo be ob- tained, although the filver employed be ed with copper or iron: becaufe the falts formed by thefe two metals with nitrous acid are deliquefcent, and are not fo eafily cryftal- lizable as the falt with bafis of filver. In this cafe the folution ought to be evaporated, if it be neceflary; and the cryftals of filver will be cryftallized by cooling, while the copper or iron will remain diffolved. When the colored liquor is poured off, cryftals will be found fufficiently white and almoft pure; but to purify them perfectly, they ought to be drained, diffolved again in very pure water, and again cryflallized : then after they are well drained from the liquor, they will be found perfect and beautiful. This even is a method of feparating filver from the allay of copper, or of iren; and of obtaining from fandard filver, or filver alloyed with copper, as fine and colorlefs a folution as if tefted filver had been employed. Lunar cryftals then are a true lunar nitre, or niire with bafis of filver ; and they accordingly have the property of deflagrating upon burning coals, almoft as well as nitre, with bafis of fixed alkali. When this experiment is made, the filver is found after the detonation incrufted upon the furface of the coal, in its metallic fate. Notwithftanding this property which lunar nitre has of detonating with coals, a property which fhews a ftrong adhefion of nitrous acid with filver; yet this adhefion is not fufficiently ftrong to refift a certain degree of heat; fo fas 3 y CRYSTALS by calcination or diftillation thefe two fubftances may be digolned. unar cryftals may be melted with a very gentle, and lefs than a red heat. - They eafily lofe the water of their cryftal- lization, and then congeal into a black mafs, which is gerepsly caft into moulds, and is called Lapis infernalis, or unar cauflic. See Cavstic (Lunar). This Talt is very cauftic, as the effets of the lunar cauftic fhew in furgery, although it has loft a part of its acid in the fufion which it receives. This corrofive quality of lunar cryftals feems to render it unfit for internal ufe as a medi- cine; yet fome phyficians prefcribe it as a powerful eva- cuant of water, Boyle, though not a phyfician, but affifted by fome perfons of the faculty, propofes a method of ren- dering thefe cryftals of filver milder, and boafts much of them as a remedy. His method confifts in adding to 2 {olution of them in water another folution of an equal quantity of nitre, and evaporating the whole to drynefs and whitenefs, with a very gentle fire, by which a portion of the fpirit of nitre is intended to be taken away without fufing the faline mafs ; after which, this faling powder is to be made into pills, by forming it into a pafte with fome bread and water. Little kill in chemiftry is requifite to thew, that nitre thus mixed with lunar cryftals, being incapable of ating upon it, cannot render it milder, but muft leave it un=- changed. Secondly, by the manner of drying this mixture of lunar cryftals and nitre, lefs of the caufticity of thefe cryftals is deftroyed than by forming them into lunar cauftic, in which operation they fuftain a heat fufficient to fufe and to blacken them, and confequently lofe more of their acid. After thefe confiderations, we cannot believe that this remedy of Mr. Boyle is fo mild and innocent as it has been reprefented. This is certain, that, notwithftanding the praifes given it by this philofopher, its ufe has not yet been eftablifhed in medicine. Lunar cryftals are called by Lemeri witriol of filver ; but as they contain no vitriolic acid, this name does not fuit them, and ought only to be given to the falt formed by the union of vitriolic acid with filver. See SILVER. CRYSTALS of COPPER, or of VENUS. By thefe names is meant a falt formed by the union of the acid of vinegar with copper. neg ; This EEE i A A aa EE —— * C.U PE L This combination may be made by diffolving directly copper in goed diftilled vinegar; but it is made much more commodioufly, and more expeditioufly, when the copper employed has been previoufly formed into verdegrife ; becaufe the copper in the verdegrife is already divided and pene- trated by a certain quantity of acid of wine: verdegrife therefore is always ufed for the preparation of cryftals ef copper. ‘This operation is very fimple. It confifts in diffolving verdegrife in good diftilled vinegar till this acid be faturated. For this purpofe a matrafs is to be ufed, and t > be fet in a fand-bath with a gentle heat. When the vinegar diflolves the verdegrife, it takes a fine greenifth-blue color. Some chemifts call it alfo Tinéture of Venus. When it ceafes to a&k on the verdegrife, it is to be decanted, evaporated, and cryftallized. The beautiful greenifh-blue cryftals formed are cryftals of copper. When this falt is expofed to a dry air, it lofes eafily the water of its cryftallization, and its furface is reduced to a lighter-colored fea-green powder, The acid of vinegar does not ftrongly adhere to the copper in this combination. It may be entirely feparated from it by diftillation ; and as it had loft moft of its fuperabun- dant water when it united with the copper, it may by this method be obtained in its greateft concentration. It is called radical vinegar, and improperly fpirit of Venus. See thefe words. The principal intention of chemifts in making cryftals of Venus is to obtain radical vinegar. But this preparation is alfo ufed by painters; for which reafon large quantities of it are manufattured, and it is generally fold under the name of diffilled verdegrife ; probably becaufe diftilled vinegar is employed in its compofition. = Sec CoPPER and VINE- GAR. CUCURBIT. A cucurbit is a chemical veflel em- ployed in diftillation, when covered with its capital or head. Its name comes from its lengthened fhape, by which it refembles a gourd : fome cucurbits, however, are {hallow and wide-mouthed. Cucurbits are made of copper, tin, lafs, and ftone-ware, according to the nature of the fub- Wh to be diftilled. A cucurbit provided with its capital conftitutes the veflel for diftillation called Alembic. See this word, and PLATE 1. CUPEL. A cupel is a wide-mouthed earthen veflel, like a flat cup, from which refemblance it has been named. The DA MP '$ The ufe of cupels is to contain gold and filver mixed with lead in the operations of refining and of aflay, and to abforb the litharge and other fcorified matters formed in thefe operations. For this reafon cupels ought to be made of dry, porous earths, capable of refifting the action of {trong fire, and of fluxes. : ‘The afhes of wood and of bones are the moft proper earths for cupels. Thefe afhes ought to be perfectly. burnt and calcined ; that is, till they become white, fo that they contain no more inflammable principle, which might re- vivify the fcorified metals, and occafion an ebullition during the operation. They ought alfo to be well lixiviated, and deprived of all faline matter to avoid their fufion. : To form cupels, afhes thus prepared ought to be mixed with water into a pafte, to which a proper form is given by means of a mould. Sometimes they are made into a pafte with fome beer; a fmall quantity of clay is added, that they may be moulded more conveniently. Calcining tcfis made of clay are allo called by fome artifts cupels ; becaufe they have the fame form as the refining and effay cupels. See Essay and PraTE 1. fig. 10. CUPELLATION, Cupellation is an operation by which gold and filver are refined or eflayed by fcorification with lead upon the cupel. See REFINING and Essay. AMPS. Thefe are noxious and even fatal exhala- tions or vapors, which infeft fubterranean places, and particularly mines, if the air be not frequently renewed. The inftances of fatal accidents caufed by thefe vapors are too frequent. Moft of them kill animals fo fuddenly that no affiftance can be given. Although all thefe vapors produce fimilar effets, and occafion fudden and mortal faintings and fyncopes, yet fome differences may be obferved in the properties and modes of acting of thefe vapors in different places. From which: we may prefume, that they are not all exaétly of the fame nature, Some of them are vifible, and appear in form of a fog; fuch is that which is found in a quarry near to the mineral waters of Pyrmont; and of which Dr. Seip has given a defcription in the Philofophical Tranfactions. This vapor has a fulphureous fmell, deftroys infects, birds, and in general D A MP § general all animals which approach it, with fymptoms fimilar to thofe which animals {uffer when placed under an exhaufted receiver of an air-pump. ate ; Others, though perfeétly invifible, produce the fame effects. Such are, fays the learned tranflator of Lehman, thofe which ifflue from a cave in Hungary, fituated near Ribard, at the foot of Crapack mountains. Thefe vapors “are fo fatal that they kill birds, while in their flight they approach teo near to the mouth of the cave. Amongft the noxious mineral exhalations we may alfo - place thofe which are found in the mines of Sal-gem in Poland. Thefe frequently appear in form of light flocks, threads, and webs, like. thofe of fpiders. They are re- markable for their property of fuddenly catching fire at the lamps of the miners with a terrible noife and explofion. “They inftantly kill thofe whom they touch. This explo- fion is a true fubterranean thunder. Similar vapors are found in fome mines of foffil-coal. : As arfenic is the greateft poifon cf all mineral fubftances, as it is volatile, and abounds in almoft all mines, many authors have fuppofed that damps contained fomething arfe- nical. But this opinion is fo far from being proved, that ftrong reafons induce us to believe that they are of a different nature. We are certain, and I know it from my own expe- - rience, that a perfon may be a confiderable time expofed to a large quantity of vapors of arfenic without fuffering any of the {ymptoms occafioned by damps, and even without being much incommoded. Secondly, the effects produced by arfenic taken internally, even in a large quantity, although terrible, and always fatal, are not nearly fo fudden as thofe occafioned by damps, which inftantaneoufly kill. Thirdly, no obfervation or experience have afcertained the arfenical rature of any damps; and it is even demonftrable, that many of thefe noxious mineral vapors are nothing elfe than volatile fulphureous acid. © Latftly, all thofe which are not evidently volatile fulphu- reous acid appear to be pure, or almoft pure phlogifton difengaged from bodies without burning. They occafion exactly the fame accidents as exhalations of liver of fulphur, of burning coals, and of matters undergoing the putrid or fpirituous fermentations. The great inflammability of thefe vapors, when they are confined, and condenfed to certain degree, fuch as thofe of coal-mines, is a demonftrative proof of this opinion. : By DAMP 8 By art we may perfectly imitate thefe vapors. We know that when acids diffolve ‘impegfeét metals, they take from them a confiderable part of their inflamméble. principle. This principle is almoft totally diffipated in vapors during thefe folutions; and if the operation be made in a clofe veflel, when this is uncorked, and a lighted candle brought near its mouth, the vapor contained inftantly catches fire, and occafions an explofion fo much more violent as the quantity of vapor was greater. This phenomenon may be chiefly obferved when iron is diflfolved in vitriolic acid diluted with a certain quantity of water. If after this ex-- plofion the bottle be left open, fuppofing the folution of the metal to be continuing, and the flame of a candle applied to the mouth of the containing veflel ; - the phlogifton, which is continually difengaging and forming vapors, but freely, and without condenfation, will continue to burn in fuch a manner, that a light-bluifh flame will be feen at the mouth, of the veflel, fuch as the flame of phlogifton always is when the phlogifton is not in an oily ftate. Although thefe experiments are generally made by means of a folution of filings of iron in vitriolic acid, I doubt not that, by employing proper management, fimilar vapors might be produced from other imperfect metals, efpecially . thofe which moft eafily part with their phlogifton when aif. folved by acids, as tin, zinc, and regulus of antimony ; and I doubt not that if thefe metallic vapors were colleted in a {ufficient quantity in a clofe place, where the air was not renewed, that they would produce the {ame fatal acci- dents as thefe called damps. All thefe confiderations induce us to believe, that moft of thefe noxious fubterrancan vapors are nothing but phlo- gifton difengaged from certain fubftances, and circulating within the earth. It proceeds from bitumens and from ful= phur, which undergo different alterations and decompos fitions. - Almoft all chemifts and metallurgifts agree in believing, that mineral exhalations contribute to the production of metals. This opinion is fo much more probable, that, as phlogifton is one of the principles of metals, (if it be true that thefe mineral exhalations are nothing elfe than phlogif- ton) and as this principle is. then in a {tate of vapor, and confequently much divided, perhaps reduced to its fmalleft integrant particles, it is then in its moft favourable ftate for combination : it is therefore probable, that when thefe exha- lations meet earths difpofed to receive them, they combine Voi. IL. T more D AMPS more or lefs intimately with thefe earths, according to their nature. Perhaps this is the chief operation of the grand myftery of metallifation. See MeTavLs and PrLOGIS- TON. (1) DECAN. . rl) The damps or vapors mentioned in this article are of two kinds, inflammable and uninflammable. The inflammable kind is probably, as the author believes, fimilar to the vapors produced by the folutions of iron, zinc, tin, and perhaps of other metallic {ubftances in vitriolic and marine acids. See Gas. This vapor is chiefly found in coal mines, and fometimes in lead mines, as in thofe of Mendip hills. Like the inflammable vapor of metallic folutions, it is lighter than atmofpherical air, and confequently floats chiefly near the roofs of mines: miners, therefore, when it is accidentally inflamed, or when they purpofely fet fire to it, to deftroy it, lie flat on the ground, and thus efcape burning. "This inflammable vapor may perhaps be produced by the dev eompofition of pyritous matters, with which moft mines, efpeci- ally coal mines, abound. In this decompofition of ppyrites expofed to air and moifture, the vitriolic acid of the fulphur attacks and diffolves the iron, while the inflammable principle of the fulphur is difengaged, and forms this vapor, The uninflammable vapors of mines and {ubterranean places are much more noxious than the former. They feem to be fimilar to the uninflammable vapors produced by the combuftion of in- flammable bodies, as of charcoal, and by fermenting and effer- vefcing fubftances. See Gas. Like thefe, they are noxious to animals, extinguifh flame, and are heavier than atmofpherical air; for they are chiefly placed at the bottom of the pits in which they are found : accordingly, in the cavern near Pyrmont; men- tioned in the text, a man may ftand upright without any other inconvenience than an uncommon heat of his lower extremities, ‘but he cannot without danger keep his head bent down. The fymptoms attending perfons expofed to fuch vapors fhew fuffi- ciently that they are not noxious merely by interception of common air, but by fome quality which almoft inflantly affects and deftroys the powers of animal life. Some perfons digging in a cellar in Paris were found dead, Riff as ftatues, with open eyes, and ftanding in the pofture of digging. At Chartres, in France, a perfon going down into a cellar into which a baker had been ufed to throw hot embers from his oven, was inftantly killed ; and when his body was opened, his lungs were found {potted with black marks; his inteftines fwoln, red and inflamed ; and the mufcles of his legs, thighs, and arms, feemed to be feparated from each other and from the adjacent parts. See Bomare's Did. &’Hiftoire Naturelle, at the word EXHALAISON. ~ M. Beaumé DECOCTION DECANTATIONS. By this word is meant the {€pa- rating of a clear liquor from a fediment, by pouring it gently. DECOCTION. This word is Split Bo ay either the action of boiling a fubftance in water, of the water itfelf in which the fub{tance has been boiled. Decoction is only applicable to matters containing fome principles foluble in water; fuck, particularly, are vege- table and animal matters ; and this operation is rather ufed for the purpofes of medicine than of chemiftry. It is neverthelefs very neceffary to know well the nature and principles of fubftances fubjected to decoction, that it may be properly managed, and that the principles with which the water becomes impregnated may be known. Thefe principles muft evidently be fuch as are not fuffi- ciently volatile to-rife with the heat of boiling water, if the decoction fhould be long continued. { Hence it follows, that plants, or other matters contain- ing volatile principles, cannot be proper fubjects of decoc- tion, when thefe principles are required. In this cafe-the matters may be infufed with water in clofe veffels without heat, or with a heat lefs than that of boiling water. But on the contrary, when it is not intended to preferve the volatile parts, or when the matters contain none that are volatile, then decoftion may be employed. It even becomes neceflary when the matters to be treated are folid, and of a compact and clofe texture ; becaufe then the water could not extrac its principles without a boiling heat. Mot foft animal matters, as fleth, tendons, fkins, may be boiled conveniently in water ; becaufe they contain no principle volatile with a boiling heat. Water extras from them nothing but a gelatinous fubftance, and fome oily parts which float on the furface of the water. M. Beaumé gives an account of two perfons that were expofed to the damp of a cellar in Paris. One of them died. The other was with difficulty brought to life, This perfon related, that the time from his entry into the cellar to that when he loft his fenfes did not exceed two minutes : during which time, he neither felt jan nor oppreffion. At the inftant when he was lofing his fenfes, e found himfelf in a moft pleafing fituation; an inexpreffible delirium, and agreeable reverie took poffeflion of his imagination. This agreeable {enfation at the very gates of the tomb, was quite free from any of the horrors that ufually accompany death. At ‘Jaft ke loft all motion and fenfation, and remained in that fitua- tion about an hour and a half, till he was found and carried up from the cellar. Rozier. Qbfervations de la Phyjique, Fan: 1774. . 2 Decodtion DECOMPOSITION "Pecotion is the only method by which all the gelatinous fubftance of ithe folid parts of animals, as bones and horns, can be extracted. All vegetable matters which are inodorous, and particu- larly thofe which are hard, as roots, barks, are generally boil- ed when an extraction of their principles by water is required. However, many of thefe fubftances ought not to be boiled ; thofe particularly, the principles of which, when extracted by water, fuffer fome change by a continued heat. Peruvian bark, for inftance, which is inodorous, and con- tains nothing volatile, feems capable of being treated with- out any inconvenience by boiling ; neverthelefs, Mr. Beaumé- obferves, in his Elements of Pharmacy, that the infufion of this bark made without heat really contains more of its principles than the decoétion. The caufe of this is, that water extralts from bark not only the fub- ances of which it is naturally a menftruum, fuch as the gummy and extractive matters, butalfoa confiderable quan- tity of refinous fubftance, which keeps well diffolved in the .water by means of the former matters, till it is expofed to heat, and then it immediately feparates and precipitates. Many other vegetable matters exhibit the fame phenome- non; therefore a general rule may be eftablifhed, that “deco&ion ought not to be employed but when abfolutely neceflary, that is, when the fame principles or the fame quantities of thefe principles cannot be obtained ‘by an infufion, and that without heat, if it can be fo done, con- fidering that the proximate principles of vegetables are generally fo delicate, and fo fufceptible of change and decompofition, that frequently the moft gentle heat changes much their nature and properties. See EXTRACTS. DECOMPOSITION o BODIES. The che- mical decompofition of bodies confifts in the difunion and feparation of their principles and conftituent parts. * "This decompofition ought neceflarily to be diftinguifhed from a mere mechanical divifion, as the following reflections will thew. * The word Decompofition is ufed by Boyle, Newton, and other Englith authors very differently from the definition given in the _ text, Thefe authors employ this word to fignify ¢¢ the compofition or junction of two or more bodies which were previoufly com. pounded of other parts.” Many Jaze Englifh authors have how- ever adopted the French fignification of the words, decompofition, and to decompofe. ” A DECOMPOSITION All bodies in general, or portions of any matter, may be . confidered as compofed of parts feparable from each other. We cannot, ‘for inflance, conceive an atom of matter fo fmall, but that this atom may be confidered as divifible into parts ftill fmaller; and this undoubtedly has given the idea of the infinite divifibility of matter, a fubject which we! do not mean to examine here, becaufe it does not belong to chemiftry ; befides that, it is like all thofe in which the confideration of infinity is concerned, that is, an abfurdity feems to be joined with evidence. As chemiftry is a fcience folely founded on experience, we fhall confine ourfelves to what experience teaches con- cerning the divifibility of bodies. But we are certain that, bodies may be very foon reduced to fo fmall parts that we cannot further divide them, from the deficiency of our fenfes and of our inftruments. One thing is very remarkable in this divifion, called mechanical, becaufe it is performed by cutting or bruifing inftruments ; that is, that however fmall the parts be into which it reduces bodies, thefe parts are always entirely of the fame nature as the body from which thefe parts were taken. - Thefe fmall parts of bodies are called their inte- grant: parts. ‘Thus, br example, the fmalleft atoms into which mon, falt, refin, or other fubftance, can be mechani- cally divided, have all the fame properties; excepting quan- tity, which the mafs had before the divifion. Hence we ought to conclude, that this mechanical divifion cannot feparate bodies but into homogeneous parts, or parts of the fame mature: and if we had no other method of dividing bodies, the compounds would always remain fuch as nature offers to us, without caufing any other change than a diminution of quantity. The fame thing would happen, if all natural bodies were equally fimple or equally compounded. But all chemical experiments thew, that in this refpect there is a very great diverfity. ; Some bodies are fo fimple that no change can be produced upon them by any effort of art. Thefe are called by chemifts elements, or primitive principles. But thefe fimpler bodies, the parts of which are evidently more {mall and fine than thofe of bodies lefs fimple, become, in the hands of chemifts, inftruments capable of dividing thefe latter much further than can be done by mechanical in- ftruments. Thefe fimple bodies are capable of dividing molecules, which would be {till imperceptible by our fenfes, T 3 although - DELF-WARE although ‘they were much larger than they arc when they have undergone this invifible divifion. : To illuftrate this by an example. Let us: fuppofe a metallic mafs compofed of mercury and gold, in fuch pro- portion that no mercury can be forced out from the mafs by expreflion, which is a mechanical method. I fay then, that the mechanical divifion which could be made of this compound, would only feparate it into fmaller and fmaller molecules, each of which would be of the fame nature as the original mafs, that is to fay, compofed of an equal pro- portion of mercury and gold. If indeed we had inftruments and fenfes fufficiently fine, we might at length come to molecules, each of which would be compofed of one atom of mercury and gold, which by one divifion more would be feparated into two atoms, one of each of the two metals diftinétly. Thus we might obtain the mercury and the’ gold feparately, and confequently effet a decompofition of the compound fubftance fubjected to this mechanical divifion ; but the impoffibility of fuch a divifion is fufficiently demonftrated. Yet what mechanical inftruments cannot do, fire, which is one of thofe {imple bodies we have mentioned, is capable of performing. The primary parts of this element, much finer than thofe of gold or of mercury, become in the hands of chemifts inftruments inconceivably fine, which effect a feparation of mercury from gold, confequently reduce to its elements or principles the compound which has been fub- jected to. their adtion, and thus analyfe or chemically de- compofe it. See ANALYSIS, DECREPITATION. By decrepitation is meant the quick feparation of the parts of a body, occafioned by a ftrong heat, and accompanied with noife and crackling. "This effect is moft frequently produced by water contained betwixt the parts of a decrepitating body, when thefe parts have a certain degree of adhefion together. This water being quickly reduced into vapors by the heat fuddenly applied to it, rarefies.and burfts with noife the parts which comprefs it. . The bodies moft fubject to decrepitation are certain falts, fuch as common falt, vitriolated tartar, nitre of kad, the de- crepitation of all which proceeds from the water of their cryftallization, clays which are not perfectly dry, and flints. DELF-WARE. This is a kind of pottery of baked earth, covered with an enamel or white glazing, which .gives it the appearance and neatnefs of porcelain. q Some DELF-W ARE? Some kinds of this enamelled pottery differ much from others, either in their fuftaining fudden heat. without breaking, or in the beauty and regularity of their forms, of their enamel, and of the painting with which they are ornamented. i In general, the fine and beautiful enamelled potteries, which approach the neareft to porcelain in external ap- pearance, are at the fame time thofe which leaft refit a britk fire. Again, thofe which fuftain a fudden heat are coarfe, and refemble common pottery: 5379 fied 1 The bafis of this pottery is clay, which is to be mixed when too fat with fuch a quantity of fand, that the earth {hall preferve enough of its duékility to be worked, moulded, and turned eafily, and yet that its fatnefs fhall be fufficiently taken from it, that it may not crack or thrink too much in drying or in baking. Veilels formed of this earth mut be dried very gently to avoid cracking. They are then to be placed in a furnace to receive a flight baking, which is only meant to give them a certain confiftence or hardnefs. And, la ly, they are to be covered with an enamel or glazing, which is done by pouring upon the veflels thus prepared, the enamel which has been ground very fine and diluted with water. As veflels on which the enamel is applied are but flightly baked, they readily imbibe the water in which the enamel 1s fufpended, and a layer of this enamel adheres to their furface. Thefe veffels may then be painted with colors compofed of metallic calkes mixed and ground with a fufible glafs. When they are become perfectly dry, they are to be placed in the furnace included in cafes of baked earth, called feggars, and expofed to a heat capable of fufing uniformly the enamel which covers them. This heat, given to fufe the enamel, being much ftronger than that which was applied at firft to give fome confiftence to the ware, is alfo the heat neceffary to compleat the baking of it. The furnace and the colors ufed for painting this ware are the fame as thofe employed for porcelain. See Porcerain. The glazing, which is nothing but white enamel, ought to be fo opake as not to fhew the ware under it. Many receipts for making fuch enamels may be found in Neri’s Treatife on the Art of Making Glafs, with Kunkel’s Notes, and in the Encyclopedia, both which books may be con- {ulted on this fubjet. We fhall only obferve in general, T 4 that DEL F-W ARE that all thefe enamels for delf-ware are compofed of fand or flints, vitrifying falts, calx of lead, and calx of tin ; and that the fand muft be perfely vitrified fo as to form a glafs confiderably fufible. = Somewhat lefs than an equal part of alkaline falt, or twice its weight of calx of lead, is re- quifite to effect fuch vitrification of fand. The calx of tin is not intended to be vitrified; but to give a white opake color to the mafs ; and one part of it is to be added to three or four parts of all the other ingredients taken together. From thefe general principles, various enamels may be made to {uit the different kinds of earths to which they are to be applied. . To make this enamel, lead and tin are calcined together with a ftrong fire, and the fand is alfo to be made into a fritt with the falt or athes. The whole is then ‘to be well mixed and ground together. This matter is then to be placed under the furnace, where it is melted and vitrified during the baking of the ware. Then it is to be ground in a mill, and applied as we have directed. $ee CLAY, PoT- TERY, PORCELAIN, and VITRIFICATION. (m) DELI- (m) M. Bofe & Antic has publifhed a memoir concerning Delf. ware in the Mem. des S¢avans Etramg. Tom. 6. From this memoir the followirg obfervati.ns are taken. Pure clay is not a fit material when ufed alone for the making of Delf-ware. I ifferent kinds of carths mixed together are found to fucceed better. Pieces of ware made of clay alone would require too much time to dry, they would crack, and would lofe their form, unlefs they were made exceedingly thick. An addi- tion of marl is found to leflen the contraction of the clay ; renders it lefs compaét; allows the water to efcape, in the drying of the ware, without alteration of form; and affords a better ground for the enamel, which appears more glofly and white, than when laid on clay alone. The kinds of clay which are chiefly ufed in the compofition of -Delf-ware, are the blue and green. “But a mixture of blue clay and marle would not be fufficiently folid, and would be apt to fcale, unlefs it were expofed to a fire more intenfe than what is commonly ufed for the burning of Delf-ware. To give a greater folidity,. fome red clay is added, which on account of its ferru- ginous matter pofiefies the- requifite binding quality. The pro- portions of thefe ingredients vary in different i according to the different qualities of the earths employed. Three parts of blue clay, two parts of red clay, and five parts of marle, form the compofition ufed in feveral manufactories. M. D’Antic thinks that the beit delf might be made of equal parts of pure clay and | . 7 pure DELIQUESCENCE DELIQUESCENCE. We underftand by deliquef- cence the property ‘which certdin ‘bodies have to attract nioifture from the ‘air, ‘and'of becoming “thereby liquid. This property is riever found but in faline fubftances, or in matters containing ‘them. = It is caufed by the great affinity which faline fubftantes have'with water. * Hence, the more fimple thefe fubftances are,” the more alfo'th cent. Acids, for inftande, and certsin alk A are, deliquef- is, which are the moftfimple ‘of faline fubftantes, ‘are alfo the moft deli- quefeent. © Mineral acids are fo deliquefcent® that they ftrongly imbibe moifture from the air, although they are ai- ready mixed with’ a fufficient quantity of water to be fluid. ent that they be concentrated For this purpofe itis fuffici only toa certain degree. 7 Many ‘neutral falts are deliquefcent,” chiefly thofe ‘whofe bafes are not faline fubftances. Their dtids are but imper- fe@ly faturated ; and although they do ‘not ‘give the fame marks of acidity as’ when quite difengaged, they may be confidéred as ftill poflefling enough of théir activity to ex- ercife’ it on the moifture of the’circumambient air. This proves that the acids of. neutral ‘deliquefcent falts are in an intermediate {tate betwixt that of an acid quite difengaged, and that of one perfectly faturated and combined. All the phenomena which falts prefent relatively to their deliquefcence, are fo many proofs of what we have affirm- ed on this fubjeét. Rytsaalsh Salts formed by vitriolic “acid with fixed or volatile alka- lis, earths, or metallic fubftances, are not deliquefcent; although this acid be the ftrongeft of all, and which, when difengaged, moft powerfully atfradts moifture from the air. But its greater ftrength is ‘the real caufe of its forming fo complete and intimate combinations with thefe feveral fubftances as to form neutral falts which are not deliquef- cent. pure calcareous earth; but this compofition would require that the fire thould be continued twice as long as it generally is. The preparation of the white enamel with which this ware is glazed, is another effential part, in which many artifts fail. M. D’Antic recommends for this purpofe a mixture of a hundred pounds of calx of lead with about a feventh part of that.quan- tity of calx of tin for common delf, or a fourth part of calx of tin for the fineft delf; a hundred, or a hundred and ten pounds of fine fand ; and about twenty or thirty pounds of fea-falt, or {alt of glals, The DELIQUESCENCE The nitrous and. marine acids-form with abforbent earths and certain metallic fubflances, particularly with iron and copper, deliquefcent falts, from the weaknefs of the union ‘which they contrat with thefe matters, Thefe acids form ‘with’ filver, mercury, lead, and bifmuth, falts which are ‘not deliqueicent;” becaufe they combine more intimately “and completely with thefe latter metals, falda Singular phenomena are prefented by vegetable acids re- latively to the deliguefcence of the neutral. falts formed by them, The acid “of vinegar “united with fixed vegetable alkali forms a _yery deliquefcent falty called terra foliata fartari, The fame acid forms with copper a falt that is ‘not deliquefcent, as ‘we fee in the inftance of cryfals of copper, Thefe effets are direétly contrary to thofe gro- duced by the nitrous and marine acids united with the fame fubftances ; for thefe acids form with fixed vegetable alkali falts which are not deliquefcent, and with copper falts ‘which are very deliquefcent, The acid of tartar, which when difengaged is in a con- crete ftate, and far from being deliquefcent, fince it is fcarcely foluble in water, forms with iron (another fub- ftance ftjll lefs foluble) a very deliquefcent foluble tartar, ‘known by the name of tartarifed tinélure of iron, Many refearches and experiments remain yet. to be made to explain entirely the caufes of thefe fingular effects, But probably the deliquefcence or oppofite quality of falts will be found to depend on the flate of their acids, as we have already fads, a _ wil The fixed vegetable alkali is deliquefcent, the mineral:is not. The caufe ‘of which undoubtedly is, that the faline principle-of the latter alkali is combined more intimately, or with a greater quantity of matter not faline, than that of the former, as the other properties of thefe two alkalis in- dicate. Sce ALKALL Si yor _ Fixed vegetable alkali treated with quicklime becomes more deliquefcent. Volatile alkalis, which are naturally not deliquefcent, become by treatment with quicklime deli- quefcent, We cannot explain thefe phenomena without fuppofing that quicklime takes from alkalis in general a portion of oily or other matter, which binds and faturates their faline principle, when in their natural ftate. The dry extracts of almoft all vegetable matters eafily moiften in the air. But they certainly poflefs this proper- ty fo much more evidently, as a greater quantity of earthy er refinous matter, which is always depofited during the evaporation, DETONATION evaporation, has been previoufly feparated from their infu~ fions and decoctions. | Before we finifh this article we ought to obferve, that fome bodies which are net deliquefgent attract moifture from the air, and even become liquid, that is, if they be faline or foluble in water. This happens when bodies are much colder than the air to which they dre expofed. The reafon of it is, that the moifture contained in the air being always in the ftate of ‘infenfible vapors, is condenfed by: the cold of the bodies it touches, and ‘is: colleted in. drops. This effect is wery different from a true deliquef-. cence 3 but it deferves to be taken notice of, to prevent miftakes in experiments. Laftly, we muft remark, that fome bodies, after having been a long time expofed to the air, may remain apparent ly dry, although they really be in the difpofition of deli- quefcent bodies, that is, attract much moifture from the ambient air. Such, for inftance, is quicklime, which im- bibes from the air its equal weight of moifture, and re- tains; notwithftanding, its dry and powdery appearance. This proceeds from the great quantity .of earthy parts with which thole parts of the quicklime are mixed, which may be confidered as deliquefcent, although, in fa&, they do not refolve into a liquor. DELIQUIUM. This term is frequently employed by chemiils to characterize a body which is refolved into a liquor by expofure to air. In this fenfe they talk of the deliquium of a falt, as of falt of tartar, for inflance, This word is alfo frequently ufed inftead of deliquefcence. = Thus we fay, that a fale falls into a deliquium, to fignify that it is deliquefcent. DEMI-METAL. The fame as SEMI-METAL ; which ee. - DEPHLEGMATION. Dephlegmation is an ope- ration by which the fuperabundant water of a body is taken from it; and it is principally effected by evaporation or diftillation. Dephlegmation is alfo called concentration, particularly when acids are the fubjec. See CONCENTRA- TION. DETONATION. By the word detonation chemifts underftand an explofion with noife made by the fudden in- flammation of fome combuftible body. Such are the explo- fons of gun-powder, fulminating gold, and fulminating powder. As nitre is the caufe of moft explofions, the word detonation has been appropriated to the inflammation of the acid of this falt DETONATION fait witli bodies containing phlogifton, and it is frequently given to thofe inflamations of nitrous acid which’ are not accompanied with explofien. Thus nitre is faid to detonate with! fulphur, with coals, with metals, although in the ordinary method of making thefe operations, that is, in open crucibles, and with fmall quantities of detonating fub- ftances, the nitre does not truly explode, (i; DETONATION of NITRE.' The detonation of nitré is one of the moft important phenomena of chemiftry. It confifts in the inftantaneous inflammation and decompo- fition of the acid of nitre, when it immediately touches com- buftible bodies, the phlogifton of which is ignited, or when the acid is ignited. flamed. « The firft method is by applying it to a red-hot combuftible body y and the dfecond: is by making the acid itfclf red-hot, and applying a combuftible body to it in that fate. ty | --A very. neceflary remark is, that nitre cannot detonate without the concurrence of thefe circumftances now men- tioned: -Nitre'may be made red-hot, or of any degree of heat, without fhewing any fign of inflammation, provided it does not touch any inflammable matter. ri On the other fide, nitre may be heated, anda combuftible body applied to it without any inflammation. For this pur- pofe, the nitre nced only be not fufficiently hot to kindle the inflammable bodies “applied to it. Meffrs. Macquer and Beaumé fhow, ‘in their courfe of chemiftry, an experi- ment which clearly proves this truth. Some nitre is put into a crucible, and there completely fufed’ by a heat juft fufficient for that purpofe : when a black coal is thrown ito this fufed nitre, no inflammation arifes, becaufe the nitre may be melted with a degree of heat which is not fufficient to kindle combuftible Bodies ; and this degree of . heat ismneceflary for the fuccefs of the experiment. : But when nitre is red-hot, and a coal is applied to it, kindled, or not kindled, then it is inflamed with violence, and makes the coal burn rapidly. The fame event happens when nitre is thrown upon burning coals. ‘This inflam- mation lafts while thefe two fubftances touch, and any acid remains in the nitre. During this detonation a con- {iderable fmoke rifes ; but this fmoke contains no acid, as the experiment of the clyffus of nitre made in clofe veflels fufficiently proves. See CLyssus of NITRE. W hen By two ‘methods then may mitre, or rather its acid be in DETONATION When all the nitrous acid is thus burnt, and no lofiger any inflammation is excited, although more coals are added, if we examine what remains in the crucible, we fhall find that it is the fixed alkali which was the bafis of the nitre. "This alkali is called fixed or alkalifed nitre. See thefe words, and ALKALI (FIXED VEGETABLE.) The detonation may be rendered more ealy and fudden by making the nitre touch the inflammable matter in a greater number of parts; fo that when thefe two fubftances are divided into very minute parts, which are well mixed and interpofed betiwxt each other, the detonation is almoft in- ftantaneous, and is as ftrong as it can be made. When the {fubftances are thus prepared, they may be at once inflamed by-a fmall fpark of ignited matter; becaufe the ignition is very quickly and almoft inftantaneouily communicated by {mall intervals. From the accurate mixture of the two detonating fubftances proceeds the great force and violence of gun-powder. See Powper (Gun). Hence we may learn to avoid the violence of detomna-~ tions in chemical operations, by mixing very imperfeitly the nitre with the combuftible {ubftances. Let us now confider what pafles in the detonation of nitre. Mr. Macquer, in his Elements of Chemiftry, con- jectures that the detonation of nitre, which is, properly {peaking, the inflammation of the nitrous acid, cannot take place, unlefs a combination be previoufly formed betwixt this acid and the phlogifton of the combuftible fubftance ufed for the detonation; that this combination is entirely fimilar to that of vitriolic acid with phlogifton when fulphur is formed; and that, in the prefent inftance, a nitrous Julphur is produced ; but that this fulphur is infinitely more combuftible than the vitriolic fulphur, for a reafon we {hall foon fee, and even fo combuftible, that it cannot exift an inftant without being entirely burnt; hence it is in- flamed with extreme rapidity and violence as foon as it is formed. ’ "The moft effential circumftances attending the detona- tion of nitre concur in rendering this opinion probable, that is, to eftablith the preliminary exiftence of this nitrous fulphur. Firft, vitriolic fulphur cannot be formed by vitriolic acid engaged with a fixed alkali, unlefs this acid be deprived of all the water fuperabundant to its faline effence, and in a dry ftate, when it is applied to phlogifton. In DETONATION In the fecond place, to effect this combination, a degree of heat equal to that of ignition muft be applied. : Thirdly, as in fulphur not a particle of oil exifts; but the vitriolic acid is united to pure phlogifton, as the illuftrious Stahl has fully demonftrated ; if, therefore, an inflam- mable matter, which is in an oily ftate, be ufed for the “formation of fulphur, it muft be firt decompofed, and reduced to the ftate of coal, before the fulphur can be pro- duced. Sez SuLpHUR. But thefe are precifely the fame conditions which are neceflary for the detonation of nitre ; for fince the acid of nitre cannot detonate unlefs it be ignited, it muft be evidently deprived of all the water fuperabundant to its faline eflfence. In the fecond place, experience fhews that nitre cannot detonate with any matter which is in an oily ftate; for if nitre be ignited in 4 crucible, and oil, refin, fat, or other inflammable matter of this kind be added to it, no detona- tion will happen while the inflammable matter remains in its oily ftate, or till it be burnt, decompofed, and reduced to a coal; then the detonation commences, and is always proportionable to the quantity of coal produced by the in- flammable matter. Some fubftances, the phlogifton of which is eertainly in an oily ftate, fuch as tartar, faw-duft of wood, and others of this kind, do indeed detonate with nitre almoft as readily as powder of charcoal : but we may eafily perceive that the caufe of this is, that the oil of thefe fubftances, being divided by the interpofition of a large quantity of incom- buftible matters, may be exceedingly foon reduced to the ftate of coal by the heat of ignition. Several fats intimately conne&ted with the detonation of nitre may be naturally deduced from this theory, and confequently become additional proofs of it. Let nitrous acid, as much dephlegmated as poffible, be poured upon black coals, as dry and hot as they can be made, under a red-heat, no detonation or inflammation will - enfue. This is not furprifing, fince all the neceflary con- ditions for the production of nitreus fulphur arc wanting bere, and fince, in fimilar circumftances fulphur could not be formed by vitriolic acid. If an ardent coal be plunged into the ftrongeft nitrous acid, a detonation begins at the furface of the coal, which very foon ceafes ; the coal is extinguifhed, becomes black, and is not affeted by the acid. The fhort detonation upon the furface of the coal may be confidered as accidental, and not DETONATION not belonging to'the experiment ; otherwife the defonation would continue while the acid lafted. This detonation can only be caufed by a fmall quantity of nitre, formed inftanta- neoufly by the acid uniting with {ome fmall portion of alka- line falt-¢ontained in the athes of the coal, which happen to lie on its furface : therefore, when this fmall quantity of nitre is confumed, the coal is extinguifhed, and the detonation ceafes ; and ail this ought to happen becaufe the moft dephlegmated nitrous acid contains always a confiderable quantity of water fuperabundant to its faline effence ; and as it is not in the pre- fent experiment retained or fixed by any bafis, it diffipates in vapors before it can be totally dephlegmated by the heat of the ardent coal : hence in this experiment no nitrous fulphur can be formed ; neither can vitriolic acid form vitriolic fulphur in fimilar circumftances, but only volatile fulphureous acid. From thefe falls we may conclude, that nitrous acid, while free, that is, not engaged in any bafis, cannot ever contract with phlogifton fuch an union, as that a {fulphure- ous compound, or nitrous fulphur, fthall be formed; not only becaufe of the fuperabundant water it always contains, but alfo becaufe, from its want of fixity, it cannot be de- . prived of this fuperabundant water in the very act of com- bination: we may therefore affirm as a general and efta- blithed principle, that difengaged nitrous acid is not capable of detonation. If then this pure acid inflames oils mixed ‘with it, this inflammation proceeds from a very different caufe than the true detonation of nitre, as Mr. Macquer has fhewn in his Elements of Chemiftry ; nitre and difengaged nitrous acid being very different from each other, particularly with regard to detonation. See INFLAM- MATION of O1Ls. What we have faid on this fubjet clearly fhews why combinations of nitrous acid with certain bafes form nitres fufceptible of a ftrong detonation, while others of the fame acid with different bafes detonate weakly or not at all; thefe differences depending on the greater or lefs adhefion of the nitrous acid with its bafis. All thofe nitrous. {alts in which the acid is fo firmly fixed and retained by its bafis, that it may be entirely dephlegmated and ignited, are fuf- ceptible of a ftrong detonation; fuch are ordinary mitre, cubic mitre, nitrous ammoniacal falty nitres of filver, of mercury, of lead, and of bifmuth; of all which ordinary nitre detonates moft violently, and is the only one of which good gun- powder can be made; becaufe the fixed vegetable alkali, which is the bafis of nitre, has a ftronger adhefion to ‘ 3 nitrous DETONAKTION nitrous acid than any other of the fubftances foluble by this acid, i104 hi r sptiiznoz blvoy, On the contrary, all combinations in which nitrous acid is only weakly united, do not detonate, or véry weakly. Such are aitres with bajes of calcareous earths, of copper, (n) i Lik ) (n) Nitre with bafis of copper is capable'of detonating by contact with tin ; the nitrous acid ating on the tin'fo violently as to produce heat fufficient for the detonation. This experiment is thus defcribed by Dr. Higgins, in the Phil. Tranf. Vol. 63. ¢¢ Several pieces of thin fheet-copper placed vertically and at a fmall diftance from each other in the ftrong nitrous acid, diluted with half its quantity or more of water, and {uffered to remain in a clofe veflel until the acid is faturdted, afford a cryftal- line blueith- green falt, whichis to be feparated from the undif- folved copper and the fuperfluent green liquor, and kept in a well ¢orked bottle ; becaufe on expofure to air it deliquefSes. <¢ This falt taken moift, but not very wet, and beaten to the finene(s of bafket fea-falt in a mortar, is to be ftrewed to the thicknefs of a fhilling on a piece of tin-foil twelve inches in length and three in breadth. . _ ¢¢ Then the foil is to be inftantly rolled up fo as to. include the falt as it lay between the coils. The ends are to be {hut by pinching them togethcr, and the whole is to be prefed flat and clole. «¢ All this being done as quick as poffible, the firlt phenomenon is, a part of the falt deliqucfces. | «¢ 2. This part impregnated with tin changed in color, and of a thicker confiftence, begins to froth forth from the ends of the coil. “¢ 3. A ftrong frothing, accompanied with moderate warmth. 4. The emiflion of copious nitrous fumes. 5. Heat intolerable to the fingers. 6. Explofion and fire which burft and fufe the tin are not vitrifiable, the proof by acids is not fufficient to 3 afcertain Be nts so coment i EAU DE LUCE afcertain the nature of thefe ftones. To this proof muft al{6 be added that of hardnefs, which is the moft decifive, Many impure and mixed vitrifiable earths and ftones differ from each other by their colors, and other accidental particulars depending on the heterogeneous matters with which. they are united, Nature prefents to us many mixed earths and ftones, or fuch as are compofed of many kinds of different earths, as the vitrifiable, calcareous, talky, argillaceous, gypfe- 4ous or felenitic, and even the pyritous or metallic. But we cannot enter into thefe details, which are the obje& of mineralogy. We fhall obferve, that when an accurate examination of thefe compound bodies is required, the nature and proportions of the component parts may be difcovered by fubmitting them fucceflively to the’ decifive proofs which we have mentioned under the articles of the principal kinds of earths and ftones, by which their nature may be difcovered and afcertained. See in particular for the vitrifiable earths and flones, the general article EARTH, “and the word VITRIFICATION. : " EARTH-WORMS. (4d) EAU DE LUCE. Eau de luce is a kind of volatile, liquid foap, of a ftrong, penetrating fmell. "This liquor is compofcd of the liquid volatile alkali made from fal ammoniac with quicklime, and of the rectified oil of amber, fo mixed together as to produce a white milky liquor, Eau de luce cannot be prepared without certain manage- ment ; for if the volatile {pirit of fal ammoniac and reétified oil of amber be fimply mixed and fhook together, a milky (4) Eartu-Worms. Farth-worms, when moiftened with wine, or with vinous fpirits, to prevent their putrefation, and fet in a cellar in a wide mouthed veffel, are in a few days almoft wholly refolved into a flimy liquor. Stahl fuppofes that they dre impregnated with a nitrous falt which they receive from the putrid matters amongft which they live. When this liqguamen of worms is mixed with a little fixed alkali, and, after the evaporation, is fet to fhoot, the cryftals are nothing elfe than nitre. Six drams of extract were obtained by ardent fpirit from four ounces of worms; and from the fame quantity of thefe, one ounce, fix drams, and a fcruple of extra&t, by means of water. Thirty-two ounces of dried earth-worms yielded, by diftillation, thirteen ounces and a half of volatile urinous fpirit, one ounce of concrete volatile falt, four ounces and a half of empyreumatic oil, and eight ounces of a refiduum, from which were obtained, by calcination and lixi- viation, an ounce and a half of fixed alkali. Neuman. liquor EFFERVESCENCE liquor will be produced, fuch as is required; but this color difappears foon when the liquor is allowed to reft; either becaufe the volatile alkali compleatly diflolves the oil of amber when in fmall quantity, or becaufe this - oil difengages itfelf from the volatile alkali, and floats apart when in confiderable quantity. In both cafes the liquor becomes clear and tranfparent; but the milkly color is required in eau de luce. By the following receipt excel- ent eau de luce may be made. Take four ounces of rectified fpirit of wine, and in it diffolve ten or twelve grains of white foap ; filtrate this folution ; then diffolve in it a dram of rectified oil of amber, and filtrate again; mix as much of this folution with the ftrongeft volatile fpirit of fal ammoniac, in a cryftal-glafs bottle, as when fufficiently thook, fhall produce a beautiful milky liquor. If upon ‘its furface be formed a cream, fome more of the oily fpirit of wine ought to be added. This receipt is given by the author of the French edition of the London Difpenfatory. The receipt given in that work is very good, but is much improved by the obfervations, experiments, and remarks made by that author. EDULCORATION. Edulcoration is, properly fpeaking, the rendering fubftances more mild. Chemical edulcoration confifts almoft always in taking acids and other faline matters from fubftances to which they adhere; and this is effected by wathing in much water. - The wathing of diaphoretic antimony, and of the powder of algaroth, till the water comes off from thefe fubftances quite pure, may be given as inftances of edulcoration. In Pharmacy, juieps, potions, and other medicines, are faid to be edulcsrated, by adding fugar or {yrup. EFFERVESCENCE. Effervefcence is an inteftine motion excited betwixt the parts of two bodies of different natures, when they reciprocally diflolve each other. Effer- vefcences are commonly accompanied with bubbles, vapors, fmall jets of the liquid, and noife or hiffing. All thefe phenomena are occafioned by the air which difengages itfelf in almoft all folutions. tinny alfo effervefcences are accompanied with. a confiderable heat, fometimes ex- ceeding that of boiling water. This heat is occafioned by the collifion of the parts during their union. The degree of heat produced in effervefcences is proportionable to the activity with which bodies are diflolved, to the quicknefs with which the folution is made, and to the quantity of fubitances re-acting upon each other, Y 4 The 9 The moft fenfible effervefcences are obferved in tha combination of concentrated mineral acids with calcareous earths; alkaline falts, metallic fubftances, and oily matters, _ Generally the fubftances which contain a fenfible quan- tity of inflammable principle are thofe which in fimilar circumftances produce the moft heat in effervefcing with acids. Of all acids, the nitrous produces the greateft heat, when it diffolves thefe bodies. Thus, for inftance, the heat arifing from a folution of calcareous earth in nitrous acid is not nearly fo great as that which arifes from a folution of a metallic fub{tance in the fame acid, although thefe folutions are performed equally faft ; and the heat which is produced by the com- bination of nitrous acid with oils is fo great, that a flame is quickly produced. | ormmerly the word fermentation was commonly applied to effervefcences; but now that word is confined to the motion which is naturally excited in animal and vegetable matters, and from which new combinations amongfit their principles take place. This diftinction is very proper ; for a fimple effervefcence is very different from a true fermen- tation. See FERMENTATION. EFFLORESCENCE. By this expreffion chemifts denote what happens to certain bodies, upon the furface of which a kind of meal or powder is formed. EfHlorefcence is occafioned either by decompofition or by drying. ‘That which happens to Cobalt, and moft martial pyrites, is of the former kind ; and the efflorefcence obferved on cryftals of marine alkali, of Glauber’s falt, of alum, of green and blue vitriols, and of feveral other falts, is of the latter kind. EGGS. The eggs of hens, of birds in general, and of fe- veral other animals, are compofed of feveral diftinct fubftan- ces; 1. Ofathell or external coat, which in the eggs of birds has a certain hardnefs and coniiitence, although it 1s brittle, + “The matter of this fheH is a fine, abforbent earth, foluble in acids; hence if thefe eggs be fteeped in vinegar, or any other acid, they are rendered quite foft, becaufe the acid diffolves and takes away all the earth of their fhells. (¢) (2) The fhells of eggs are not only abforbent, that is, foluble by acids, butalfo calcareous, or convertible into quicklime. The earth of the fhells, and alfo the earth obtained by calcination of the other parts of the eggs, are fufible and vitrefcible by fire Sec Earra (Anuar). The » EG G 8 ’ The parts of this earth are bound together by a fmall quantity of gelatinous matter, This matter becomes very fenfible by an empyreumatic animal fmell, and by the black color which fhells acquire when expofed to fire. The thell of an egg is lined internally with a-very white, fine, and ftrong membrane. It refcmbles a very fine {kin, and is entirely of animal nature, Thefe external coverings contain the fubftance of the egg, ‘which is of two kinds; namely, a lymphatic, white, tranfparent, gelatinous, vifcous, and gluey {ubftance, called the white of the egg ; and another fubftance alfo gela- tinous, but almoft opake, yellow, lefs gluey and vifcous than the white. This latter, which is called the yolk, is of a fpherical form, and is furrounded by the white. To the yolk is annexed a {mall portion of white gelatinous matter, thicker and tougher than the reft of the white in which the embryo is contained. We do not intend here to examine anatomically the ufes of thefe feveral parts of the eco; we will confider them only relatively to their chemical properties and principles, As eggs contain the embryo of the animal, 2nd the nourifh- ment proper for it in its firft increafe, they are proper to be given as an example of the analyfis of animal feed. The white of an egg cannot be diffolved by acids or by {pirit of wine. This latter folvent, far from dividing it, on the contrary coagulates it, by taking from it a great part of its water which renders it liquid. The white of an epg'is foluble and mifcible with water, but difficultly, becaufe of its vifcidity. Spirit of wine poured into water which keeps it diffolved feparates it, and precipitates itin form of a curd. ~ In this relpect, the white of an egg refembles gummy, mucilaginous, and gela- tinous matters. It is, in fa&, a matter entirely of the nature of animal jellies, but of that kind which is coagu- lable by heat. The white of an egg, expofed to alefs heat than that of boiling water, is coagulated, hardened, and its tranfparency is almoft entirely changed to a milky-white color. ‘This fubftance contains no other principles which are volatile with the heat of boiling water, than water ; for if whites of eggs be diftilled in a water-bath, nothing but water is obtained. While they lofe this water, they become more and more hard and horny ; they refume their tranfparency, and acquire a yellow-reddith color; fo that when they are dried as much as poffible, they perfectly refemble horn. If EGG § If they are to be further analyfed, they muft be put into a retort, and expofed to a naked fire: then fetid em- pyreumatic oil with much volatile alkali is obtained ; and in the retort, when the diftillation is finithed, a coal is left like that of other animal matters. From this analyfis we fee that the white of an egg is a perfectly animalifed fub- ftance. Ses JELLY (ANIMAL). The yolk of an egg is chiefly compofed of a gelatinous matter like the white; for it alfo coagulates and hardens by heat; but it alfo contains a confiderable quantity of mild fat oil, which is in fome meafure fuperabundant, and not combined, and, in fhort, in the fame ftate as thofe oils which may be obtained from vegetable emulfive feeds by exprefiion. Thus the raw yolk of an egg when mixed with water is not entirely diffolved, as the white is; but forms with it, on account of this oily part, a white milky ‘liquor or emulfion. This animal emulfion is vulgarly called ben’s milk. ‘This fuperabundant oil of the yolk of an egg may be feparated from it, like that of moft vegetable grains, by exprefiion. But to make this operation fuccefsful, the yolk of an egg ought to be deprived as much as is poffible of its water. [or this purpofe, the eggs are to be pre- vioufly hardened, and the yolks are to be feparated, dried, and even roafted in a proper yeflel, till they become fome- what foftened by the fweating out of the oil ; they are then to be put into a prefs, and a fat, unctuous, yellowifh, and fufficiently mild oil is procured, which readily fixes itfelf in the cold. This oil has the fimell of roafted or fried eggs, from the drying and roafting given to the yolks before the exprefion. Probably this oil might be obtained by a flower and more careful drying without roafting, and confequently without any change or fmell. | From this quantity of fuperabundant oil in yolks of eggs, . we may perceive a remarkable refemblance betwixt the eggs of animals and vegetable feeds. This oil is found in all feminal matters probably for the fame reafon. §ee O1Ls (Sweet EXPRESSED), As all eggs in general are compofed of a very nourifhing fubftance, and as thofe of many animals have a very agree- able tafte, they have been much ufed as aliment. They are alfo employed in medicine and in thearts. The white of an egg is an ingredient in collyriums and cataplafms for difeafes of the eyes; and both the white and yolk in emollient and refolvent cataplafms. The oil of eggs is foftening, relaxing, ELEMENTS selaxing, and lubricating. It is employed either fingly, or formed into a pomatum with fat matters, in burns, chaps, contradtions, and other fimilar difeafes, The white of an egg, from its folubility in water, and from its coagulating by fire or in {pirituous liquors, is very, fuccefsfully employed in pharmacy, in the kitchen, and for clarifying the juices of plants, whey, fugar, fyrups, &c. See FILTRATION, The white of an egg alone forms a varnifh very white and very fhining, which 1s applied to feveral kinds of work, and particularly to pictures. Laftly, the yolk of an egg, from its oily and vifcid parts, is a proper intermediate {ubftance for the mixture by trituration of oils with watery liquors, fo as to form emulfions. Several good remarks are found upon this fubje& in Mr, Beaume’s Treatife on Phar- macy. (f ) ELECAMPANE. (gz) ELEMENTS. Thofe bodies are called by chemifls elements, which are fo fimple, that they cannot by any known method be decompofed,” or even altered ; and which alfo enter as principles, or conftituent parts, into the com- bination of other bodies, which are therefore called com- pound bedies. The bodies in which this fimplicity has been obferved are fire, air, water, and the pureft earth; for by the moft complete and accurate analyfes which have been made, nothing has been ever ultimately produced but fome one, or more, of thefe four fubftances, according to the nature of the decompofed bodies. Thefe fubftances, although reputed f{imple, may poflibly no: be fo, and may even refult from the union of feveral other more {imple fubftances: but as expericnce teaches us nothing on this fubjet, we may without inconvenience, (f) Mr. Reaumur found that eggs might be preferved during months or years, by being covered with mutton fuet, or any other fat fubttance. (gz) ELecampane. From thirty-two ounces of the roots of elecampane were obtained, by diftillation, three fcruples and a half of concrete oi!, fimilar in many, but not in all its properties to camphor. This concrete oil is ioluble in fpirit of wine, Geof- froy remarks, that it refides in the exterior part of the root, near to the bark. From an ounce of the dry root fix dram: and a half of extralt may be obtained by water, and from the fame quantity two drams and a haif by fpirit, Neuman. and EMER ¥ and we ought to confider, in chemiftry, fire, air, water, and earth, as fimple bodies; becaufe they really act as fuch in'all chemical operations. The elements are 2lfo called by chemifts primary prin- ¢iples. See Princrpres, Fire, AIR, WATER, and Earth. ELIQUATION. (5) ELUTRIATION. (i) EMERALD. (4) EMERY. (/) (5) ELiquaTion. This is an operation by which a more fufi- ble {ubftance is feparated from one lefs fufible, by means of a heat fufficiently intenfe to melt the former, but not the latter. Thus an allay of copper and lead may be feparated by applying a heat which fhall melt the lead, but not the copper. (i) ELuTriaTION is an operation performed by wathing folid fubftances with water, fiirring them well together, and hattily ouring off the water, while the lighter part remains fufpended in the agitated water, that it may be thereby feparated from the heavier part. By this operation metallic ores are cleanfed from earth, flones, and other lighter unmetallic particles adhering to them. (k#) EMERALD, Smaragdus, is a precious fone, contained by feveral unequal fides, forming irregular prifms. Its color is green : with a moderately {trong heat it becomes blue, but re- covers its original green color when cold. By expofure to collett- ed folar heat, emeralds were rendered white and of various colors, and foon afterwards were fufed, by which they loft part of their weight and hardnefs, See Dramonps. But M. DD*Arcet could not fufe an Emerald in the intenfe and long continued heat of a porcelain furnace, although the color and tranfparency of the Eme- rald were thereby altered, Emeralds have the property of fhinihg in the dark after having been heated. They are the fourth in hardnefs trom diamonds; neverthelefs they are fufceptible of impreflion from a file. “Emeralds may be imitated by adding forty-eight grains of pulverifed calcined verdigrife, and eight grains of martial crocus, to four ounces of minium and two ounces of pure fand, and by keeping that mixture fufed during twenty-four hours. ; (/) Emery. Smiric. Emery isa very refractory minegal con- taining a fmall portion of iron. It is exceedingly hard, and is therefore ufed for the polithing of metals, glafs, and hard flones. Some pieces of emery contain {mall fpecks of gold, and of copper. The mineral called by alchemifts fmiris Hifpanica, and employed to adulterate gold, is with probability believed to be the metal now called platina. - 3 EMPY- EN AME L EMPYREUMA. Empyreuma is a fmell proceeding from burnt animal and vegetable matters, when they are expofed to a quick fire, particularly in clofe vefiels. ~ Empyreuma isthe peculiar fmell of burnt oils. No other but oily fubftances can produce it. As all vegetable and animal matters contain oil, and as no other fubftance contains it, hence the empyreumatic fmell muft be peculiar to burnt animal and vegetable matters; and hence alfo we may difcover oil, wherever it may be, by this fmell, which is fo diftinguithable, that it is very fenfible even when the quantity of oil is toe fmall to be difcovered by any other method. If then we perceive an empyreumatic fmell when we burn a fubftance in clofe veflels, we may conclude that this fubftance contains oil. Jf, on the contrary, no empy- reuma be perceived, we may be affured that the fubftance does not contain oil. EMULSION. An emulfion is a watery liquor, in which fome oily matter is difperfed and diffuled (but not diffolved) by the intervention of a mucilaginous or gela- tinous fubftance. . The ftate of the oil in emulfions is the caufe why they are opake, and of a milky-white color; for this milky appearance is given to all tran{parent bodics by others that have not a very diftiné& color, when they are mutually interpofed and divided to a certain degree. Neverthelefs, water and oil flightly adhere together in emulfions, by the intervention of the mucilaginous matter ; for oil agitated with water gives“but a momentary ap- pearance of an emulfion, and only during the agitation. When it is left to reft, the oil prefently rifes to the fur- face. All vegetable and animal fubflances contain an uncom- bined oil; and mugilage or jelly, being triturated with water, yield emulfions. Moft feeds and grains, all gum-refins, gummy 2nd’ refinous juices, and yolks of eggs, are capable of forming emulfions with water. Laftly, the milky juices of plants, milk, and the chyle of animals, ought to be confidered as natural emulfions. : : ENAMEL. Enamel isin general a vitrified matter, betwixt the parts of which is difperfed fome unvitrified, matter : hence enamel ought to have all the properties: of glafs excepting tran{parency., Enamels then are opake: glafles, and their opacity and colors proceed from the: unvitrified matter which “they contain. The unvitrified : matters ENAMEL ters which give opacity and various colors to enamels, arid always BA calxes. Receipts for making feveral kinds of enamel may be found in feveral books, particularly in Neri’s Yoo on Yee Art of Making Glafs, vi otes by Merret and Kunkel. a ght to be very fufible. They are aE to color or to paint feveral kinds of work which are by great heat. The white enamel is ufed to cover the earthen ware called’ Delf, to which it gives the GF of porcelain. With the other colored enamels this Io ware, porcelain, and alfo the white enamel, are painted. yee DELF-W ARE. (7m) ENS namels are glaffes containing fome opake fubftance, that is ih Es or incapable of being vitrified with the as. gree of heat requifite for the fufion of ordinary glafs. Of the latter fort are almoft all the enamels ufed, they being moftly com- pofed of glafs mixed with metallic calxes ; all w ich, not oy cepting the calx of tin, by more intenfe heat might be F78ke to tranfparent glafles. The white vitreous compoiition whic 3s the bafis of all enamels is prepared, according to Neri, by me te ing together a hundred parts of frit of calcined flints, one pares pure fal of tartar; and a hundred parts of a calx of lead an iw “This calx is prepared by calcining together equal parts of tin an lead, and reducing the fubftance fo calcined to a very fine pow- der, by bruifing it, paffing it through a fieve, boiling it Aven, decanting the water in which the finer parts are fufpended, eva- porating the water, and drying the powder ; and by repeating the calcination and fubfequent operations upon the groffer parti- cles, till they become as fine as the former. This Sompditir when {lightly fufed is to be reduced to a powder, and forme ios all the various colored enamels, by adding to it coloring {ub- flances. ‘Thus by adding to fix pounds of this compdfition, fsa ty-eight grains of magnefia, a fine wbite enamel may be prepared ; an axuce blue enamel, by adding to the fame quantity three ones of zaffre, and fixty grains of calcined copper; a furquois ie enamel, by adding three ounces of calcined copper, ninety-fi grains of zaffre, and forty-eight grains of magnefia ; A green enamel, by adding three ounces of calcined copper and fizty grains of fcales of iron ;°a shining black enamel, by adding three ounces of zaffre and as much magnefia ; a purple enamel, by adding gy ounces of magnefia; a yellow enamel, by adding three ounces © tartar and feventy two grains of magnefia ; a fea fre or Joon colored enamel, by adding three ounces of calcined | rafs an ixty grains of zaffre ; and a wiolet colored enamel, by adding two ounces of magnefia and forty-eight grains of calcined copper. Thefe oe ES SAY ENS MARTIS, and ENS VENERIS. Thefe Latin names are given to the flowers of iron and of copper made with fal ammoniac, or rather to thefe two metals fublimed by this falt. See FLowkRrs. ESSAY. Eflays are chemical operations made in ~ fmall, to determine the quantity of metal or other matter which is contained in minerals, or to difcover the value or purity of any mafs of gold or filver. We fhall treat fucceffivcly of each kind of eflay. ESSAY of ORES. Before eflays of ores can be well made, a preliminary knowledge of the nature of the feveral metallic minerals ought to be attained. Each metal has its proper and improper ores, which have peculiar characters and appearances: hence perfons, accuftomed to fee them, know pretty nearly, by the appearance, weight, and other obvious qualities, what metal is contained in a mineral. A good effayer ought to be very intelligent in this matter, that he may at once know what the proper operations are which are requifite to the eflay of any given mineral. Some remarks may be found on this fubje under the article OREs. ; As metals are very unequally diftributed in their ores, we fhould be apt to make falfe ‘and deceitful eflays, if we did not ufe all poffible precautions that the proportionable quantity of metal produced by any eflay fhall be nearly the medium contained in the whole ore. “This is effected b taking pieces of the mineral from the feveral veins of the mine, if there be feveral, or from different places of the fame vein. All thefe minerals are to be fhook together with their matrixes. The whole is to be well mixed together, and a convenient quantity of this mixture is the receipts given by Neri, and approved by Kunkel. The in- tenfity and continuance of the heat muft be attended to, as the colors both of enamels and of the tranfparent glafies imi- tating colored precious ftones, efpecially of thofe which contain magnefia, depend much on thefe circumitances. White enamels ‘may be compofed of other fubftances befides calx of tin. 'Merret propofes to fubftitute regulus of antimoay. Calcined bones, and perhaps other white earths, may be ufed for the fame purpofe. Mr. D’Arcet found that gypfum mixed with white clay, or with clay and hard fpar, formed very beautiful enamels, Perhaps fome of thefe enamels would form glazings preferable to that made with calx of tin, for covering thofe kinds of earthen ware which require, in the baking, greater heat than is fuitzble to the common enamel. to ES SAY to be taken for the eflay. This is called the Jotting of the . Qre. As eflays, particulary the firft, are generally made in fmall, eflayers have very fmall weights correfponding to the weights ufed in the great, that is, to the quintal or hundred pounds weight, to pounds, ounces, drams, &ec. The eflay quintal and its fubdivifions vary according to the difference of weights in different countries, and this occafions fome confufion, when thefe weights are to be adjufted to each other. Tables of thefe weights are found m treatifes of eflaying, and particularly in that written by Schlutter, and tranflated and rendered more com- plete by Hellot, which contains all the details neceflary for the fubject. The cuftom is to take, for the eflay quintal, a real weight of a gros, or dram, which in France is equal to 72 grains ; but as the whole dram reprefents 100 pounds, each. grain reprefents a pound anda fraction of a pound; and hence fome difficulty and: confufion arife in" making the fubdivifions. A: better method’ is thatof Mr. Heilot, which is to. make the fititious or eflay quintal equal to a-hundred real grains, and then each grain reprefents a real pound. This eflay quintal is fufficientlyr exalt’ for ores of lead, tin, copper; iron, antimony, bifmuth; and mer cury. But forores of filver and gold another reprefentation is convenient; for thefe metals, as Mr. Hellot fays, are generally in fo fmall quantity, that the button: or {mall piece of metal obtained in the eflay could ‘not be accurately weighed, if a hundred real grains were made to reprefent a quintal ;. and the difficulty of feparating: the gold from fo fmall a quantity would be’ftill greater. Thefe motives have induced Mr. Hellot-to ufe for thefe ores a fictitious quintal fixteen times greater, that is, equal to 1600 real grains, which reprefent 1600 ounces, that’ 1§; 100 Ib. or "quintal. The ounce being reprefented hy a grain, its feveral fubdivifions' muft be reprefented by fractions of a grain. Thus 12 grains of the fictitious quintal” cor- . refpond with 3% of a real grain (#); and this latter quan- tity may be accurately weighed in effay balances, which when well made, are fenfible to a much lefs weight. (n) The pounds, of which a hundred are here fuppofed to make a quiatal, are called Paris pounds, one of which contains 6216 grains: See WEIGHTS, When E5548 Y Wher 2 quintal of an ore to be effayed has been weighed, and lotted, as we defcribed- above, it is to bé roafted in. 2 teft under a muffle. It is to be wathed, if neceffary ; and, in fhort, the fame operations are to be made in {mall which are ufually done in great. Additions alfo are to be made, “and in proper proportions, according to the peculiar nature of the ore. The fluxes enerally mixed with the ore in eflays ate three, four, or Bre parts of black flux; one, two, or three parts of calcined borax; and one half of that quantity of decrepitated common f2lt: The more refractory the ore is; the more neceflary is the addition of thefe fluxes : then the whole mixture is to be fufed either in a forge, or in a melting or effay furnace. To make eflays well, all poffible attention and accuracy, are to be employed. This object cannot be too much attended to; for the leaft inaccuracy in weighing, or lofs of the fmalleft quantity of matter, might caufe errors, fo much greater, ‘as the difproportion betwixt the weights employed and thofe reprefented is greater. ‘The moft minute accuracy therefore is neceflary in thefe operations. For inftance, the effay balances ought to be fmall, and exceedingly juft. ‘The ore ought not to be weighed till it has been reduced to grofs powder fit for roafting ; be- caufe fome of it is always loft in this pulverization. When. the ore is roafted, it ought to be covered with an inverted tet ; becaufe moft ores are apt to crackle and difperfe, when firft heated. To make the fufion good and compleat, the precife degree of fire which is requifite ought to be employed ; and when it is finifhed, the crucible ought to be Rruck two or three times with fome infirument to facilitate the difengagement of the parts of the regulus from the fcoria, and to occafion their defcent and union into one button of metal. The crucible ought not to be broken, nor its contents examined till it is perfectly cold. Upon breaking the crucible, we may know that the fufion has been good, if the fcoria be neat, compact, and equal ; if it has not overflowed or penetrated the crucible; if it contain no metallic grains; ‘and if its furface be fmooth, and hollowed in the middle. The regulus or button ought to be well colleted, without holes, or bubbles, and to have a neat convex furface : jt is then to be feparated from the fcoria, well fcraped and cleaned ; and, laftly, is to be weighed. If the operation has been well made, its weight fhows the quantity of metal which gi real quintal of ore will yield in the great. If the Yor. I. > Z perfect ESSAY erfeit fuccefs of this eflay be in any refpeét -doubtfil, it'ought to be repeated ; but the beft method at all times is to make feveral effays of the fame ore. Some fmall dif- ferences are always found, however well the effays may have been made. By taking the medium of the refults of the feveral operations, we may approach, as nearly as poflible, the true product of the ore. Laftly, as mines are not worked, nor founderies efta« blithed “(which cannot be done without confiderable ex= pence) till the ore has been eflayed, ten or twelve real: pounds of the ore ought to be previoufly effayed; and: eflayers ought to be furnithed with neceffary furnaces and inftruments for thefe larger effays. : We now proceed to give fome examples of eflays of ores. To effay a lead ore, for inftance, which is not very refrac= tory, let one or more quintals of this ore be grofly pow dered, and roafted in a teft till no more fulphureous vapors. be- exhaled, and then reduced to a finer powder ; it is then to be accurately mixed with twice its weight of black flux, a fourth part of its weight of clean filings of iron and of borax. Thefe proportions are given by Mr. Cramer. The mixture is to be put into a good crucible, or rather into a teft; it is then to be covered with a thicknefs of two or three fingers of decrepitated fea-falt; the crucible is. to be clofed, and placed in a melting furnace, which is to. be filled with unlighted charcoal, fo that the top of the crucible fhall be covered with it. Lighted coals are then to be thrown upon the unkindled charcoal, and the whole is left to kindle flowly, till the crucible be red-hot ; foon after which a hiffing noife proceeds from the crucible, which is occafioned by the reduction of the lead : the fame degree of fire is to be maintained while this noife continues; and is afterwards to be fuddenly encreafed, fo as to make a perfet fufion; in which fate it is to be continued during a quarter of an hour ; after which it is to be extinguifhed 3 and the operation is then finifhed. The filings of iron: are added to the mixture, to abforb the fulphur, a certain quantity of which generally remains united with the lead ore, notwithftanding: the roafting. We need not fear left this metal thould unite:with: the lead and alter its purity ; becaufe although the fulphur thould! not hinder it, thefe two metals cannot be united. The refraltory quality of the iron. does not impede the fufion; for the union it forms with the fulphur renders it fo fufible, that it becomes itfelf a kind of fluxs This ! E'SS'A Y This addition of iron in the eflay of lead ores would be ufelefs, if the ores were fufficienti Hips 3 hg rss ere ufficient] y roafted, fo that no ead ores generally contain fome filver, and fomet; Se Jd of 85 wherefore, otter Hr res bee » and the regulus of lead collected and wei it ought to be tefted, to difcover the or ed ou | uantit i rE Zn as Domai ias thefe load EA, y of Sve: it gold, utton of filver remaining upon th to be effayed by parting, to afcertain the WL i” pi if there be any. ! Than The details for the eflays of all oth i oe ota 1 be ie in this lo cives the fubjeCt of feveral books Ri h iy confilied, The oft of tic Rocke oo) Coren, may be It s are Cramer’ Ryn (Ars Docimafiica), and Schlutter’s Work a oe into French by Mr. Hellot. We fhall find m v 9 ings relating to this matter under the articles. O eo MELTING of ORES. (0) rks ESSAY (0) The effaying of ores is a matter of fuch i mifry, to arts, and to the wealth of i ag she, SUE as Wat pe _author o the Dictionary has otnit- » by adding to the feveral articles of of metals the methods of effaying theft sebabidn fhall here only obferve in rs that X Te ne ye prathied for effaying ores 5 imperfect Mono od BS erally efpecially, are infufficient to procure the whole quantit of m : 1 Sopigiugd In ores, or even fo much as is obtained in the fimelt ” 2 arge quantities of ores ; and that therefore the refult of flay 3 4 not to be confidered as the precife quantity contained in 21 0 ut generally only as an inaccurate approximation to that qua iu ey sles afer hes She caufe of the want of fuccefs of thefo ¢ alkaline falts employed as fluxes to ya peli ae a pry Bale bo mr fo, wh of the {fulphur of the ore ins ; whi by upiting with thefe falts, Da a‘hepar of Fhe ens he no gepethul of all folvents. He propofes therefore to omit he Ack flux, and other alkaline falts, and to 2dd nothing to he ore ut powder of charcoal, and fome fufible glafs, This the , he fays, he learned from Mr. Cramer, and has bimfel pis with much fuccefs in the effays of iron and copper: but i oe Hopes: Weng fubftances could not fuftnin ; o effeCt the fufion and vitrificati th Uimetallic parts of the ore without being partly Gpasd "he Z 2 o found E $§ S$ AY SSAY of the VALUE of SILVER, to examine Wad) Ze quantity of alloy mixed with it. Tibi common method of examining the purity of filver, is by mixing it with a quantity of lead proportionable © 3 c ‘quantity of imperfect metals with which it 1s fuppo ke to be alloyed ; by tefting this mixture; and Afteroan ks y weighing the remaining button of filver. ~The lofs $ weight which the filver fuffers by cupellation fhews the quantity of imperfect metals which it contained. ” We may hence perceive, that the effay of filver i nothing elfe than the refining of it by cupellation. Tien y difference betwixt thefe two operations 1s, that when | ver is tefted merely for the purpofe of refining it, its va we is generally known ; and it is therefore mixed with the 0 proportion of lead, and tefted without any neceflity o attending to the lofs of weight it fuftains during the gperi- "tion ; whereas in the effay all poilible methods ought i be employed to afcertain precifely this lofs of Weight, le firft of thefe operations, or the mere refining of vet, is made in the great, in the {melting of filver ores, an io mints for making money. Sez REFINING. The fecon operation is never made but in fmall ; becaufe the eieparaes of fmall operations are lefs than of great, and the requilite accuracy is more eafily attended to. The laft operation is our prefent fubject, and is to be performed in the follow- ral firft, that the mafs or ingot of filver, of which an effay is to be made, confifts of twelve parts per- fetly equal, and thefe twelve parts are called Deny weights. Thus if the ingot of filver be an ounce woe t cach of thefe twelve parts will be ¢; of an ounce; oF if it be a mark, each of thefe will be 5 of a mark, &c. 3 lence if the mafs of filver be free from all allay, it is calle lve: of twelve penny-weights ; if it contains tz of its weig ht of allay, it is called filver of eleven penny-weights; if 15 of its weight be allay, it is called filver of ten penny- t neceflary to add in the effays of thefe latter metallic mat- Rs rer by which the Fafoon might be completed with lefs heat. As we confider this as a’ confiderable improvement n the art of effaying ores, we fhall, to the articles of the foyer! ores, add not only the procefles commonly prefcribed, but i thefe of Mr. Gellert, according to the method here mentioned. See Oris. weights; EF § SAY weights; and thefe ten penny-weights or parts of pure filve are called fine penny-weights. : We ought to obferve here .concerning thefe penny- weights, that eflayers give alfo the name penny-weight to a weight equal to twenty-four real grains; which latter real penny-weight muft not be confounded with the former, which is only ideal and proportional ; and fuch a confufion is the more likely to take place, as this ideal penny-weight is alfo, like the former, divided into twenty-four ideal grains, which are called fine grains. ; An ingot of fine filver, or filver of twelve penny-weights, contains then 288 fine grains ; if this ingot contains zis of allay, it is faid to be filver of eleven penny-weight and twenty-three grains; if it contains x75 of allay, it is called filver of eleven penny-weight and twenty-two grains; if it contains 34%, it is called filver of eleven penny-weight and ten grains; and .fo on. Laftly, the fine grain has alfo its fractions, as §, % of a grain, &c. As effays to difcover the value of filver are always made in fmall, effayers only take a fmall portion of an ingot for the trial, and the cuftom in France is to take thirty- fix real grains for this purpofe, which is confequently the largeft weight they employ, and reprefents twelve fine penny-weights. This weight is fubdivided into a fufficient number of other fmaller weights, which alfo reprefent fractions of fine penny-weights and grains. Thus eighteen real grains, which is half ‘of the quantity employed, re- prefent fix fine penny-weights; three real grains reprefent one fine penny-weight, or twenty-four fine grains; a real grain and a half reprefent twelve fine grains; and 4% part of a real grain reprefents 1 part of a fine grain, which is only »55 part of a mafs of twelve penny-weights. We may eafily perceive that weights fo fmall, and eflay balances, ought to be exceedingly accurate. Thefe balances are very fmall, fufpended and inclofed in a box the fides of which are panes of glafs, that they may be preferved from duft, and that their motion may not be affe&ted by agitated air, fo as to diforder their action. When an eflay of a mafs or ingot of filver is to be made, the cuftom is to make a double eflay. For this purpofe, two fiftitious femi-marks, each of which may be equal to thirty-fix real grains, are to be cut from the ingot. Thefe two portions of filver ought to be weighed very exactly; and they ought alfo to have been taken from oppofite fides of the ingot. Z 3 ‘ Pegfons E S$ S$ AY Perfons ‘accuftomed to thefe operations know pretty nearly the value of filver merely by the look of the ingot, and fill better by rubbing it on a touchftone. By the judgment they form of the purity of the ingot, they regus J the quantity of lead which is to be added to it, as this quantity muft be always proportionable to the quantity of imperfe& metal mixed with the filver. Neverthelefs, this proportion of lead to the alloy has not been precifely determined. Authors who treat of this {fubject differ much. They who direct the largeft quantity of lead fay, that thereby the alloy is more certainly de- ftroyed ; and others who direét a fmall quantity of lead retend, that no more of that metal ought to be ufed than is abfolutely neceffary, becaufe it carries off with it always fome portion of filver, Every eflayer ufes his own partigulay method of proceeding, to which he is attached. To afcertain thefe doubtful points, three chemifts of the Academy of Sciences at Paris, Meflrs. Hellot, Tillet, and Macquer, were appointed by the French Government, They were directed to afcertain every thing concerning the eflay of gold and of filver by authenticated experiments, made under the infpeGtion of a minifter whofe fuperior knowledge is equal to his defire of public good, and in prefence of the officers of the mint. The experiments made by thefe chemifts, and the con- fequent regulation, have determined that four parts of lead are requifite for one part of filver of eleven penny-weight and twelve grains, that fix parts of lead are requifite for filver of eleven penny-weight, eight parts of lead for filver of ten penny-weight, ten parts of lead for filver of nine penny-weight, and fo on in the fame progreflion. Two cupels of equal fize and weight are to be chofen. The cuftom is to ufe cupels of fuch 2 fize, that their weight thall be equal to that of one half of the lead employed in the eflay ; becaufe fuch cupels have been found capable of imbibing all ‘the litharge formed during the operation, “Thefe cupels are to be placed together under 2 muffle in an eflay-furnace. The fire is to be kindled, and the cupels to be made red-hot, and to be kept fo during half an hour at leaft before any metal be put into them. This precau- tion is neceflary to dry and calcine them perfectly ; becaufe if they contained any moifture or inflammable matter, an ebullition and effervefcence would be occafioned in the efizy. When the cupels are heated fo as to become almoft white, the lead is to be put into them; the fire is to be | oo encreafed, ¥ S$ 3 AY. encreafed, which is done by opening the door of the afh- hole fo as to admit air, till the lead Becomes red, fmoking, and is agitated by a motion of its parts called its circulation, and till its furface becomes fmooth and clear. “Then the filver, previoully beat into {mall plates for its eafier fufion, is to be put into the cupels; the fire is to be continued, and even encreafed, by putting hot coals at the mouth of the muffle, till the filver fhall have entered the lead, thatis, till it have melted and mixed with the lead. When the melted matter circulates well, the heat is to be diminifhed by taking away, partly or entirely, the coals put at the mouth of the muffle, and by clofing more. or lefs the doors of the furnace. The heat ought to be regulated fo, that the eflays in the cupels fhall have furfaces fenfibly convex, and fhall appear ardent, - while the cupels are ets red ; that the {moke fhall rife almoft to the roof of the muffle ; that undulations fhall be made in 2ll direGtions upon the furfaces of the effays, which are called circulations ; that their middles thail be fmooth and furrounded with a {mall circle of litharge, which is continually imbibed by the cupels. The eflays are to be kept in this ftate till the operation is finifhed, that is, till the lead and alloy have foaked into the cupel: and the furfaces of the buttons of filver being no longer covered with a pellicle of litharge, become fuddenly bright and fhining, and are then faid to lighten. If the operation has been well conducted, the two eflays ought to become bright nearly at the fame time. When the filver has been by this operation well refined, we may fee, immediately after it has brightened, the furface of the filver covered with rainbow colors, which quickly undulate and crofs each other, and then the buttons become fixed or folid. The management of the fire is an important article in effays. For if the heat be too great, the lead is {corified and imbibed by the cupel fo quickly, that it has not fuffi- cient time to feorify and carry along with it all the alloy ; and if the heat be too little, the litharge is gathered upon the furface, and does not penetrate the cupel. The eflayers fay then that the eflay is chogked or drowned. In this cafe the effay does not advance, becaufe the litharge covering the furface of the metal defends it from the contat of air, which is abfolutely neceffary for the calcination of metals, See CaLciNaTION and COMBUSTION. Z 4 We ES 5 AY We have above related the marks of a fuccefsful effay, The heat may be known to be too great, from the con, vexity of the furface of the melted metal ; from a tog ftrong circulation ; from the too vivid appearance of the ¢upel, fo that the colors given to it by the litharge cannot be diftinguithed ; and laftly, by the fmoke rifing up to the roof of the muffle, or not being at all vifible, from its being fo ardent and red-hot as not to be diftinguithable. "In this cafe the heat mut be diminifhed by fhutting the door of the ath-hole: Some effayers, for this purpofe, put round the cupels fmall, oblong, cold pieces of baked clay, which they call inflruments. ~~ "If, on the contrary, the melted metal have a furface not very fpherical, relatively to, its extent; if the cupel appear dark colored, and the fmoke of the eflay do only creep upon the furface; if the circulation be too weak, and the fcoria which appears like bright drops have but a dull motion and are not foaked into the cupel ; we may be aflure thatthe heat is too weak ; much more may we be aflured of it when the metal fixes, as the eflayers call it. In this cafe, the fire ought to ‘be encreafed by opening the door of the afh-hole, and by placing large burning coals at the mouth of the muffle, or even by laying them acrofs upon the cupels. | 3 "As foon as the lead is put into the cupels, the fire is to be encreafed, becaufe they are then cooled by the cold metal, and the lead ought to be quickly melted, to prevent its calx from colle@ing upon its furface in too great quantity before it be formed into litharge ; which it would do, and be difficultly fufed, if the heat were too weak. " When the filver is added to the lead, the heat muft be ftill encreafed, not only becaufe the filver cools the mafs, but becaufe it is lefs fufible than lead. And as all thefe effects ought to be produced as quickly as poffible, more _ heat is at length given than ought to be continued ; and therefore, when the filver has entered the lead, the heat is ta be diminifhed till it becomes of,a due intenfity for the operation. “ During the operation the heat ought gradually to be augmented to the end of it, both becaufe the metallic mixture becomes lefs fufible as the quantity of lead dimi- nifhes, and alfo becaufe the lead is more difficultly fcori- fiable, as it is united with a larger proportion of filver. Hence the effays muft be rendered very hot before they ighten. brig i a2 When ES S$ AY "When thé operation is finithed, the cupels are left in the fame heat during fome feconds, to give time to the laft portions of lishaeag to be entirely abforbed; becaufe if any of, it. remained under the buttons of filver, it would fick to them. The fire is then allowed to extinguith, and the cupels to cool gradually, till the buttons have entirely fixed, particularly if they be pretty large; becaufe if they cool too quickly, their furfaces fix and contract before. the internal mafs, which is thereby fo ftrongly comprefied as to burft through the external folid coat and form vegeta~ tions, or even to be entirely detached from the reft of the. mafs and diffipated. This is called the wegetation of the button, It ought to be carefully prevented, becaufe fmall bits of filver are fometimes thrown out of the cupel. Laftly, when the buttons are thoroughly fixed, they are to be difengaged from the cupels by a fmall iron utenfil while they are yet hot, otherwife they could not be dif- engaged clean and free from part of the cupels which ftrongly adhere to them when the heat is much diminifhed. Nothing then remains to compleat the eflay but to weigh the buttons. The diminution of weight which they have - fuftained by cupellation will {how the purity or value of the ingot of filver. : ¢ We Sught to obferve, that as almoft all lead naturally contains filver, and that after cupellation this filver is mixed with the filver of the ingot in the button of the eflay ; before we employ any lead in this operation, we ought to know how much filver it contains, that we may fubtract this quantity from the weight of the button, when we com- pute the finenefs of the River of the ingot eflayed. For this purpofe eflayers generally cupel a certain quantity of their lead feparately, and weigh accurately the button of filver it yields : or, at the fame time when they eflay filver, they put into a third cupel, in the muffle, a quantity of lead equal to that employed in both their eflays; and when the operation is finithed, and the buttons are to be weighed, they throw the fmall button produced from the lead alone into the feale which contains the weights; and as this exaltly counterpoifes the fmall portion of filver which the effhy buttons have received from the lead employed in the cupellation, the weights will fhew precifely the quantity of filver contained in the ingot, and thus the trouble of calculating is prevented. The {mall button of filver procured from the cupellation of lead alone is called the witnefs. But to prevent this trouble, eflayers E $ SAY effayers generally employ lead which contains no filver, fuch as that from Willach in Carinthia, which is therefore procured by eflayers. ; | In the fecond place we fhall obferve, that a certain quantity of filver always paffes into the cupel, as refiners in the great have long obferyed, and which happens alfo in effaying fmall quantities. The quantity of filver thus ab forbed, varies according to the quantity of the lead employed, and the matter and form of the cupels; all which objeéts will undoubtedly be determined by the above mentioned chemifts. Jey © The cupellation which we have now defcribed is exactly the fame for effays, by which the produce of a filver ore, or of an ore of another metal containing filver, is deter- mined. But as thefe ores contain frequently gold, and fometimes in confiderable quantity, when thefe effays are made, the buttons of filver obtained by the effays ought to be fubjedted to the operation called parting. See SILVER, ReriNinG, Furnace (Essay), MuFrLE, and i 2 ¢p) M. Tillet has publifhed a memoir, fhewing that eflays of filver made in the common method are uncertain and not to be depended upon, ‘and that this uncertainty proceeds from the dif- ferent quantities of filver abforbed by the cupel in different eflays, according as the heat, and other circumftances happened to vary. He therefore propofes, in order to render efiays accurate, to extract fram the cupel the quantity of filver it has abforbed during the operation, and to add this particle of filver to the button, as thefe two contain the whole quantity of filver in the matter eflayed. The variations in the different refults of different effayers, or of the fame effayer at different times, upon the fame mafs of filver, are fufficient proofs of the uncertainty mentioned by M, Tillet. Thefe variations are occafioned, according to that - author, principally from the following caufes: 1. From the 1n- accuracy of the balances and weights employed. 2. From the faulty fufion of the mafs to be eflayed ; by which means, the contained alloy may be unequally -diffufed. 3. From the im- purity of the lead, efpecially from its Contalaing filver, which is not always equally diffufed through its s. 4. From the different proportions of lead ufed by different eflayers. 5. From the difference of the intenfity ‘of heat; for, if the heat be not fufficiently intenfe, the filver will fill contain a portion of alloy ; and if the heat be too intenfe, too much of the filver will € imbibed by the cupel. 6. From the want of care in picking the’ fall particles of filver which frequently adhere to the fides of ’ | c ESSAY ESSAY of the VALUE of GOLD. The fititious weights ufed to determine the purity of gold, and to efla this metal, are different from thofe of filver. See the preced- ing article. A mafs of gold perfectly pure, or which con- tains no alloy, is ideally divided into 24 parts, called carats ; this pure gold is therefore called gold of 24 carats. the cupel feparately from the principal button. 7. From the {purting which fometimes happens unobferved by the eflayer, and which may further falfify the effays of other pieces included under the fame muffle, by the falling of the particles thrown out of ene cupel into others adjacent, But with all the attentions to avoid thefe caufes of error, the author obtained different refults from different effays of the fame mafs of filver. Nor could he, by any method, make his different effays confiftent with each other, but by adding to each button the particle extra&ted from the cupel ; and this method he found by accurate experiments to be perfeétly exalt. M. Tillet obferved, that the quantity of lead dire€ted in the regulations eftablithed in confequence of the report made by Meflrs. Macquer, Hellot and Tillet, is not fufficient to purify the filver perfeily from its alloy. He neverthelefs approves of the faid regulation, and confiders the weight of the alloy retained: by the button, as fome compenfation for the weight of the filver abforbed by the cupel. And as it is a conftant falt, that the more lead is ufed, the greater is the lofs by the abforption of the cupel, he remarks that a regulation directing a larger proportion of lead for France, than is ufed in other countries, would be difadvantageous to that kingdom, as thereby the filver of the fame denomination wou!d be required to be finer in that than in other countries where a lefs proportion of lead was employed. He obferves that the above-mentioned rule, ¢ that the more lead is ufed, the greater is the lofs by the abforption of the cupel,” does not extend to quantities of lead much above double the ufual quantities. Thus thirty-two parts of lead to one of filver will not occafion more abforption than fixteen parts of lead. For the refining fcarcely takes place till the extraordinary quantity of lead be gone, and the filver is only or chiefly carried into the cupel along with the copper. Accordingly, he found that he could render the filver finer by ufing four parts of lead at firft, and afterwards adding two more parts when the irifes began to appear, than by employing all the fix parts of the lead at once. By this method of dividing the quantity of lead, the lofs of filver by abforption was greater. M. Tillet did not find, that by em ploying bifmuth alone or mixed with lead, his eflays were more certain . than when lead alone was ufed. He obferved, however, that the addition of bifmuth made the filver purer, but occafioned # greater abforption by the cupels I ESSAY If the mals or ingot contain 5; partof its weight of alloy, the gold is then of 23 carats; and if it contains 2% or vs of alloy, it is gold of 22 carats, &c. Hence we fee that the carat of gold is only a relative and proportional weight, fo that the real weight of the carat varies according to the total weight of the mafs of gold to be examined. If this mafs of gold weighs a mark, the real weight of the carat will be »; of eight-ounces, which is equal to a mark. If the mafs . weigh an ounce, the carat will be 5% part of an ounce, or 24 grains. If ‘it is only a penny-weight or 24 grains, the real weight of a carat will be one grain; and foon. For greater accuracy, the carat of gold is divided into 22 parts, which’ are relative and proportional weights, as the carat itfelf is. Thus 57 of a carat of gold is +7 of 75, or the 733 of any mafs of gold; and the gold which con- tains an alloy equal to the r55 part of the whole mafs is called gold of 23 carats and $7 gold which contains 753 of alloy is gold of 23 carats and 42 3 and fo on. The real weight now generally ufed in the operation for determining the purity of gold, is fix grains. This weight then reprefents 24 carats. The half of this weight, or three real grains, reprefents 12 carats. According to this progreffion, we fhall find that ¥ of a real grain reprefents one carat, and the tg parts of a grain reprefents the 5% of -a carat, or the yi part of a mafs of gold to be eflayed. As thefe weights are exceedingly {mall, fome effayers employ a weight of 12 grains, which muft be very conve- nient. When a mafs or ingot of gold is to be effayed, fix grains are to be cut off, and exaétly weighed : alfo 18 grains of fine filver are to be weighed. Thefe two metals are to be cupelled together with about ten times as much lead as the weight of the gold. This cupellation is conducted precifely like that of the eflay to determine the purity of filver, excepting that the heat muft be raifed a little more towards the end of the operation when the efflay is going to brighten. Then the gold is freed from all alloy but filver. If the quantity of copper or other alloy deftruc- tible by cupellation be required to be known, the remaining button is accurately weighed. The diminution of weight from the fum of the weights of the gold and of the filver determines the quantity of this alloy. ; The button containing gold and filver is then to be flattened upon a polithed piece of fteel, and care muft be taken to anneal it from time to time, to prevent its fuss A an EF T HER and cracking. By this method it is reduced to a thin plate, which is to be rolled up, in order to be parted by aqua-fortis. See the word PARTING. The diminution found after the parting from the original weight of the gold eflayed, fhews the whole quantity of alloy‘contained in that gold. ~The eflay for determining the purity of gold is then made by two operations : the Fett, which is cupellation, de- prives it of all its imperfect metals ; and the fecond, which is parting, feparates all the filver from it. By antimony alfo gold may be purified, which is a kind of dry part- ing. By this fingle operation, all the imperfect metals, and filver with which gold is allayed, are feparated. Ses PuriricaTioN of GoLp by ANTIMONY. See alfa GoLp, SILVER, REFINING, Essay of the VALUE of SILVER. ESSENCES. Effential oils are fometimes called ¢/~ fences. Thus we fay, eflence of cinnamon, of turpentine, &c. to denote the eflential oils” of thefe fubftances. See Oivs (EssENTIAL). ETHER. Ether is a white, tranfparent liquor, of a peculiar and penetrating fmell. Ether is very volatile : it may be entirely diftilled without leaving any refiduum, or faffering any decompofition or’ alteration. It is more vola- tile and inflammable than reétified {pirit of wine. Its flame refembles the flame of fpirit of wine; but it is fenfibly much greater, whiter, and more luminous. It is alfo ac- companied with a flightfmoke or foot, which fpirit of wine is not. Ether does not mix with water, as {pirit of wine does, in all proportions ; but ten parts of water are required to diffolve one part of ether. This liquor has alfo a power of acting upon all oily and fat fubftances. From thefe eflential properties ether appears to bea fub- ftance exactly intermediate betwixt ardent fpirits and oils, as has been proved in the elements of chemiftry. See SPIRIT (ARDENT), and OIL. Ether has-been but lately known by chemifts. From certain paflages indeed of fome old chemical books, we ‘ may infer that ether was not entirely unknown to their authors ; but they have not mentioned it diftinétly, nor have they fufficiently defcribed its properties, or the manner of making it: wherefore no attention was given to it, ‘till the Cadet of chemifts was excited by a publication in the Philofophical Tranfa&ions' for the year 1730, by a German who calls himfelf Frobenius, (which however is gi . fuppofed ETHER fuppofed to, be a feigned name) in which he relatés thé experiments he had made on that liquor, to which he firft ave the name ether. Sincé that time, many chemifts ve made experiments on this matter. At firft they made ether difficultly and in fmall quantities, and at length abundantly and eafily ; paysicatarly fince Mr. Hellot com- s municated to feveral artifts a procefs which he received from 4 foreign chemift. This procefs has been printed in the Encyclopedia with confent of Mr. Hellot. ‘Since that time, Mr. Beaumé has operated more than any other chemift on ether. He has publifhed the details of his experiments and refearches, not only upon ether, but upon all the other fubftances produced from a combination of fpirit of wine with vitriolic acid. This forms the completeft treatife on this fubjeé which has hitherto been publi ed. Vitriolic acid is not the only acid from the mixture of which with fpirit of wine ether may be produced. The nitrous, marine, and. acetous acids have alfo been found capable of forming, with fpirit of wine, liquors poflefled of all the effential properties of ether ; but differing from ether, properly fo called, or vitriolic ether, by properties peculiar to each. We fhall {peak fucceflively of thefe dif- ferent ethers, beginning with the vitriolic, called henaly éther, becaufe it is the chief one and the firft difcovered. “The following procefs for making this ether, which is the beft hitherto publifhed, is extracted from Mr. Beaume’s differtation. : oe Put two pounds of perfectly re@ified fpirit of wine into a glafs retort, and pour upon it at once two pounds of well concentrated vitriolic acid. Ls i This acid being much heavier than the {piri of wine, finks directly to the bottom, and does not mix with the {piri of wine. Shake the retort gently, and repeatedly, that the two liquors may mix. The mixture will boil, and become ‘very hot. Vapors will iflue from it with a loud hiffin noife, and a fweet penc¢trating fmell. ‘The mixture will then af- fume a yellow-reddifh color. Place the retort ina fand- bath, warmed by degrees to the fame heat with itfelf. Lute fo it a receiver, in the fide of whichis 2 fmall hole, and diftill the mixture by a heat fufficiently intenfe to make it quickly boil and to keep it boiling. At firft a very fweet fpirit of wine will pafs into the receiver, after which the. éther will commie, which may be diftinguifhed by ftriz form- éd on the upper part and neck of the retort. Continue the diftillation with the [ame degree of fire, and from iz ETHER to-time unftop the fmall hole of the receiver, till you pér— ceive, upon applying your nofe near this {mall hole, a fuf~ focating fmell of volatile fulphureous acid. Then the re- ceiver ought to be unluted; and the contained ‘liquor, which will be nearly eighteen ounces, muft be quickly’ oured into a glafs bottle, which ought to be well ftopped. . his liquor is a mixture of a very dephlegmated part of the fpirit of wine, of a fweet penetrating {mell, which fles at firft; of ether, which was formed during the diftillation ; of a little oil ; and fometimes alfo of a fmail quantity of fulphureous acid; both which fubftances pafs frequently with the laft portions of the ether, particularly if the diftillation has been too long continued. To fepa~ rate the ether from thefe other fubftances, put the whole mixture into a glafs retort, with a little deliquiated fixed alkali, to abforb and retain the fulphureous acid; and diftill very flowly in a fand-bath, with a very gentle lamp heat, till you have made one half of the liquor pafs over. The liquor that rifes in this diftillation, called alfo refification, is ether. Before the Count de Lauraguais had difcovered that ether was mifcible with water in a certain proportion, the cuftom was to put the ether after this diftillation into a phial with diftilled water, and to fhake together thefe two liquors. - The ether rofe quickly to the furface, and floated on the water ;' from which it might be feparated by a funnel, as oik may from water, and obtained unmixed. But this is evident ly bad management: for in the firft place, the water thus ‘mixed diflolves about one tenth part of its weight of ether before it is faturated, all which is loft; and in the fecond place, for the fame reafon that water diffolves fome ether, the ether alfo diffolves a certain quantity of water, by which it is weakened, and its properties altered, as Mr. Beaumé has obferved. Bias The produion of ether is one of the moft beautiful and inftructive phenomena of chemiftry. Spirit of wine, which 1s at once inflammable, and mifcible with water in all pro- portions, differs from any oil by containing a more con~ fiderable quantity of water, which enters its compofition as # principal or conftituent part. This being eftablithed, if we deprive {pirit of wine of part of that aqueous principle by which it differs from oils, it ought to afflume the cha- racter of oil, and to approach fo much more to an oily nature, as it has been deprived of a greater quantity of the’ watery principle which conftitutes it {pirit of wine, and’ By which it differs from oil. ‘But this is precifely what! PNT happens ETHER | happens. te it in the production of ether, and in the ana+ lyfis of the remaining mixture after the formation of ether. "Concentrated vitriolic acid having a power of attracting .water ftrongly, does, when mixed with {pirit of wine, ac~ cordingly at “firft unite with the water which the fpirit of wine may contain fuperabundantly: and its action would not extend farther, and it would not feparate the watery principle from the {pirit of wine, if a heat were not appli~ ed fufficient for diftillation ; for ether cannot be obtained from this mixture but by diftillation. But when by the diftil- ling heat the power of the vitriolic acid to attract water is encreafed, that acid then becomes capable of feparating the watery principle of the fpirit of wine and of uniting with it. As this is done gradually, fo the fpirit of wine which rifes in diftillation ought to be more and more changed by the action of the vitriolic acid. 7 . This accordingly happens; and very diftinétly. The firft liquor which rifes in this diftillation is a portion of . fpirit of wine, very volatile, penetrating, and dephlegmated; but which has not been deprived of its watery principle, and therefore retains the eflential properties of fpirit of wine. _ The liquor which rifes next is fpirit of wine, deprived of part of its watery principle by vitriolic acid. It confe- quently is {pirit of wine efentially altered, and approximat- ed to the nature of oil, in proportion to the quantity of watery principle which it has loft. This is ether, which differs from fpirit of wine in being no longer mifcible with water in all proportions, and in emitting a whiter and more brilliant flame, accompanied with fome fuliginous fmoke. Thefe properties by which ether differs from fpirit of wine chara&erize fo well its oily nature, that moft chemiits confider this liquor as a very volatile oil. It feems, how- ever, to be rather an intermediate fubftance betwixt oil and fpirit of wine.” The folubility of ether by water makes us chiefly confider it in this light; for what oil, properly fo called, can be diffolved by water as ether can? - If the diftillation of the mixture be continued after the ether has rifen, the vitriolic acid, ftill continuing its action upon the fpirit of wine already altered, takes at length from it all the watery principle by which it differs from a true oil, and hence ought to leave it in the ftate of oil. Ac- cordingly, after the ether has pafled over in diftillation, an oil ifs which wants none of the effential properties of ; , true ETHER true oil, as it is not mifcible with water, burns with a fu= liginous fmoke, leaves a refinous coal, &c. This oil, thus created in fome meafure during the operation, is known by the name improperly given to it, of Sweet Oil of Vi- iriol. From all this we might infer, that if ether ready prepared were mixed and diftilled with concentrated vitriolic acid, it ought to be changed and transformed into fweet oil of vi- triol. Accordingly Mr. Beaumé obferved, that this did happen in an experiment he made, an account of which is given in his Diflertation on Ether. When the fweet oil of vitriol is diftilling, the vitriolic acid alts alfo upon the phlogifton of the remaining part of the fpirit of wine, and unites with one part of the inflammable principle. Hence we may fee at the fame time much fulphureous, volatile, fuffocating acid pafs in diftillation. But as the vitriolic acid which forms it then becomes charged with all the water which it has taken from the {pirit of wine, this firft fulphureous acid, although very quick and penetrating, is very aqueous, and has not much acidity. : By continuing this diftillation, with a graduated fire, to perfe&t drynefs, more of this fulphureous acid is raifed, which becomes more and more acid ; fometimes alfo a little concrete fulphur is fublimed to the neck of the retort to- wards the end of the diftillation, and a fixed coal remains, as we ought to fuppofe ; for the fame fubftances are obtain- ed by diftilling to drynefs a mixture of any oil with con- centrated vitriolic acid. 8ee OIL. From all that has been faid concerning the ndture and properties of ether we may conclude, that this {ubftance is nothing elfe than fpirit of wine deprived by vitriolic acid of a part of its aqueous principle, and thereby approxi- mated to the nature of oil. Some chemifts believe that vitriolic acid is a conftituent part of ether. This opinion, although it is not demonftrated, is not however deftitute of probability, and deferves to be examined by experiments. For, on one fide, 2 more copious and diftinct acid is con- tained in all oils than in fpirit of wine; and on the other fide, the particular properties by which ethers formed by the nitrous, marine, and acetous acids differ from vitriolic ether, feem to be owing to adhering portions of the acids with which thefe ethers are prepared. This queftion re- quires a particular examination. Vor. IL. A a Ether ETHER Ether is not employed in the arts, although it appears capable of being ufefully employed in many cafes, and par- ticularly in the folution of certain concrete oily matters for the preparation of varnifhes ; but its high price prevents its introduction into the arts. As ether is the moft volatile and evaporable of all known liquors, and as in general liquors produce a degree of cold proportionable to the quicknefs of their evaporation, as Mr. Beaumé difcovered, and feveral others have obferved ; therefore a very great degree of artificial cold may be pro- duced by means of ether. Mr. Beaumé has funk the mer- cury of Reaumur’s thermometer to 40 degrees below the freezing point, by applying linens foaked in ether to the ball containing the mercury ; and he makes this fine expe- riment every year in his courfe of chemiftry conjointly with Mr. Macquer. Ether, like all thin and volatile oily matters, has the property of taking gold from aqua regia ; but as it is more fubtle than any other of thefe matters, it produces this effect better. Yor this purpofe, ether ought to be poured upon 2a folution of gold in aqua regia, and the two liquors mixed together by fhaking the containing phial. When this mixture is left to reft, the ether foon difengages itfelf from the aqua regia, and floats on the furface of the acid liquor, which being deprived of its gold is rendered white, while the ether has now acquired a yellow color from the gold it contains. This is an expeditious method of making a tincture of gold, or portable gold. We ought to obferve that the gold which thus pafles into the ether flill retains a certain quantity of aqua regia. Ether is employed in medicine. As a very thin and vo- Jatile inflammable matter, it acts powerfully on the nervous fyftem, like all the matters of this kind. Frederic Hoffman was one of the firft who employed it as a fedative and an- tifpafmodic. The famous mineral anodyne liquor of this phyfician is nothing elfe than fpirit of wine, in which are (7) Mr. Amonftons, in a Memoir of the Academy of Paris, (1699) and more particularly, M. Richman, in a Memoir of the Academy of Peterfburg, (1747) have obferved that cold was pro- duced by evaporating fluids. Dr. Cullen difcovered, that the cold thus produced by evaporating fluids was confiderably greater in vacuo than in air, See Efays Phy/. &3 Liter. Edinburgh, vol. 2, 1746. diffolved ETHER diffolved fome ether and fweet oil of vier: i virtues to the ether. SR. asa, ince ether has become more common and b : ne n etter k many phyficians preferibe it fingly, in the dofe of oer on Sion drops _upon a bit of fugar, ‘which is to be eat or to be diffolved in fome proper liquor and drank. It js given in atulent colics, obftinate hiccups, convulfive, hyfterical affections, and other diforders of this kind. It Certain] produces frequently excellent effets ; but, like all other ge Wo Jomenss, it fometimes produces none cveral perfons have affirmed, that ether appl; d ter- naly to the back of the neck, or to the rp Giff] ON and as it were by enchantment, head-achs and meagrims. I have tried it in all dofes upon myfelf for de Seas but without fuccefs ; but we cannot from ence i Ben os at it may not have better effects upon other or HER (ACETOUS). Since the difcovery of the $ er defcribed in the preceding article, chemifts have en- eavoured to obtain fuch a liquor from fpirit of wine by Moms of other acids ; and accordingly they produced it firft Deans of the nitrous acid, then by the acetous, and : the m . eak {i r Pi ys ! » the arine. We fhall {peak fucceffively of thefe The difcovery of the producti production of ether by the acet acid was made by the Count de Lauraguais. This — made by mixing together equal parts of re@ified {pirit of Jie, and concentrated acid of vinegar obtained by diftil- ng cryftals of copper, called the Spirit of Venus, or radi- 2 vinegar, This mixture is to be diftilled in the manner gsied for vitriolic ether, and a confiderable quantity of a liquor 1s obtained, which is pofleffed of the eflential Jualities of cher, as Spichted in the former article, but Ich has alfo fome of the acidi jar fi rl) a, ¢ acidity and peculiar {mell of When this ether is mixed with liqui Vhen t - id fixed alkali, 2 again diftilled, or rectified by a fo heat, ey piobier ether is obtained, free from fuperabundant acid, and much (r) Ether diflolves all effential and exprefled oi i r dif ; oils, animal Smpyreapuatic oil; refins, and almoft erie ambergrife. It tlolves difficultly petroleom and oil of amber. It precipi- sarge olan of antimony from aqua regia, and filver from ni- iid 3 t takes fpots of greafe from filks without affeting Aa2 liker EP THER liker to true ether. It retains, however, the fmell, not of the acid, but of the inflammable part of vinegar. We obferve, that by this procefs a greater quantity of ether is obtained than by diftillation with vitriolic acid, which fhews that the acid of vinegar is eflentially fitter to produce ether than the vitriolic acid. This difference muft undoubtedly be attributed to the great quantity of ardent {pirit, which is one of the principles of the acid of vine- gar, and which perhans already approaches the ftate of ether. See VINEGAR (RapicaL). As this difcovery has been but lately made, the proper- ties of the acetous ether, and the phenomena which its refiduum may afford, have not yet been fufficiently exa- mined. ETHER (MARINE). The difcovery of the true procefs for making ether by means of the marine acid, 1s the lateft which has been made on this fubjeét. The Marquis de Courtanvaux has communicated his procefs te the Academy of.Sciences. The difficulty with which marine acid unites in general with inflammable fubftances has retarded the difcovery of marine ether ; for no ether can be obtained by treating the moft concentrated marine acid with fpirit of wine in the ordinary method, by which the other ethers are procured. Able artifts, and particularly Mr. Rouelle and Mr. Beaumé, had attempted unfuccefsfully to procure ether by diftilling fmoking marine acid with fpirit of wine. Mr. Beaumé, indeed, in his Differtation concerning Ether, has given a procefs, by which he affirms, that he had obtained a {mall quantity of marine ether. This procefs confifts in making the fumes of the marine acid and of the fpirit of wine meet together in the fame receiver. But the quantity of ether obtained by this method was very fmall. The procefs alfo is troublefome, and even imperfect, as Mr. Beaumé " himfelf declares he would not have publifbed it in that imperfect ftate, but becaufe the poffibility of the faét had been denied. What he fays may be feen in his Diflertation. en Ether. (s) Oth : thers (s) The method employed by Mr. Beaumé for obtaining 2 marine ether, namely, by making the vapors of fpirit of wine and thofe of the marine acid meet and unite together in the fame receiver, althou gh it did not {ucceed well with him, has been fuccefs- fully attempted by Mr,Woulfe, This ingenious Chemilk candenied . the ETHER ~ Others, and particularly German chemifts, had attempted to employ for this purpofe a marine acid which was united with a metallic fubftance, fuch as the butter of antimony and had obferved the fingular phenomena which happened in thefe mixtures. The Marquis de Courtanvaux has perfectly fucceeded by employing the fmoking fpirit of Libavius, which is a highly concentrated marine acid obtained from corrofive fublimate by tin, and impregnated with a confiderable quantity of this metal. Py This the united vapors of the {pirit of wine and of the marine acid by making them pafs from the receiver, through a tube, into {pirit of wine contained in a bottle, and thofe which were not thus condenfed through another tube into more fpirit of wine contained in another bottle. By diftilling and cohobating with flaked lime the liquors in the receiver and in the two above- mentioned bottles, he obtained a very fubtle and penetrating ether, which upon being mixed with water caufed a violent ehul- lition, although it was perfeétly free from any acid, Sez a de- feription of the apparatus employed by Mr. Woulfe, and many goats particulars concerning diftillation, in the Phil. Tran/ ol. 57. | Mer. le Baron de Bormes has publithed in the Memoires des S¢avans Etrangeres, Tom. 6. the following proces for making a marine ether by means of zinc ; by which method a greater pro= duce of ether may be obtained, and with lefs trouble, than in any other manner before difcovered. PROCESS or MARINE ETHER. “¢ Take twelve pounds of ordinary fpirit of f2lt, diftilled a fe- cond time over more fait, in order to render it more pure and free from all vitriolic parts. Saturate this acid with flowers of zinc, and digeft it during 24 hours, taking care not to add an more flowers of zinc till the former be diffolved, and the offer. vefcence finifhed. Filtrate this folution, and fill £ of a glals retort with it. Set the retort in a fand-bath, and didil by a very gentle heat, and draw over all the phlegm that will come. It is not neceflary to lute the vefigls, for all that paffes is only phlegm the acid being obftinately retained by the flowers of zinc. This firft operation is only intended to concentrate the marine acid. *“ When your folution becomes thick, tranfparent, and of a deep golden color, let the fire ceafe, and the veflels cool. The folu- tion will be then reduced to a quarter of its former bulk. When it cools, your liquor will fix and have the appearance of greate Add to it, when cold, fix pounds of very pure and well dephlep- mated fpirit of wine, by degrees, and at the fame time, keep Aa 3 faking ET HER This fmoking liquor, mixed with an equal part of fpirit of wine, and diftilled together, eafily produces a confi- derable quantity of a liquor pofleffed of all the effential properties of ether, and which may be confidered as a true marine ether. The tin contained in the fpirit of Libavius is feparated and precipitated in form of a white powder. "This ether, like the others, muft be re@ified to be obtained in its greateft purity. Some refle®ions concerning its nature will be found at the end of the following article. ETHER fhaking the retort.. The matters during their folation, will be- come very hot. When the retort is become fo hot that there re- mains no danger of its breaking, add the reft of your {pirit of wine. Replace your retort in the fand-bath, previouily heated nearly to the temperature of the retort, and leave it to digeft during eight days, or till all the matter be diffolved, excepting 2 powder which depofits, and is of no ufe in the operation, Then filtrate all the liquor, and put it again into a dry clean re- tort. Set the retort in a fand-bath, and fit to it a receiver {uffi. ciently large for the circulation of’ the fpirits, but do not lute the joinings of the veflels, for however well your {pirit of wine has been retified, you will draw over half the quantity of phlegm. ““ Begin your diftillation by a very gentle heat, which you may gradually augment till the liquor boils a little. The phlegm, I fay, will pafs firft. ““ When you begin to fee firiz in the neck of the retort, and to perceive an agreeable fmell fpread over the laboratory, throw away the phlegm, and replace the receiver. Lute carefully the joints, and continue the fame heat till all the aromatic {pirit of wine has pafled. At this time the matter in the retort will have become thick and like melted wax. Now the ether will be formed and begin to pafs. The fame heat is to be continued till the matter in the retort be dry, when the heat ought to be en- creafed, that the faveer oil, which is like a fine effence of citron, may pafs. This oil will fwim upon the Ether, and the diftilla. tion 1s to be continued till no more of it paffes. ¢ We may obferve, that if the fire be raifed too much before the matter is reduced to a dry mafs, it will fwell, and fall back again into the receiver, which would make the operation fail. ¢¢ When no more can be diftilled, let all cool ; and when the retort is but juft warm, unlute the receiver, {eparate the liquor from the fweet oil by means of a funnel or {eparating glafs, and fet them apart in bottles well ftoppered. *¢ When you would have the ether pure, take the clear liquor, and diftil it with the moft gentle heat of a lamp. Take the aro. matic fpirit of wine that remains afier drawing off the ether, and ET HTE-ER ETHERT(NITROUS). This ether is obtained by mixing nitrous acid with {pirit of wine, but with peculiar circumftances. In the writings of ancient chemifts traces of the nitrous as well as of the other ethers may be found; but thefe traces are neither clear nor precife. The firft perfon who publithed a fatisfactory account of this liquor, and who thewed the true method of obtaining it, was Mr. Navier, a Phyfician, at Chalons-fur-Marne, and Correfpondent of the Academy of Sciences. His procefs, which he com- and pour it back on the refiduum in the retort, which ought to have been carefully ftopped to prevent its attralting the moifture of the air, which it does moft powerfully. Proceed as you did be. fore, and you will obtain more fweet oil, ether, and aromatic fpirit of wine. This may be repeated till almoft the whole of your dromatic {pirit be converted into fweet oil and into ether. The number of thefe repetitions cannot be determined in order to obtain the whole of the fweet oil and ether, as it depends much on the preparation of the flowers of zinc, on the quality of the fpirit of falt and of the fpirit of wine, and on the manner of conduling the operation. However, we may fay, that if thefe circumftances be proper, a good operator will obtain at leat two pounds of ether and four ounces of {weet oil. ¢¢ This marine ether appears to me to be more penetrating and fragrant than the vitriolic ; and the {weet oil is equal if not fu- perior to all aromatic eflences either in fmell or {ubtlety. I be. lieve that this is the true eflential oil of wine, as much purified as it can be. ¢ In this operation no fulphureous fpirit is obtained, as when the vitriolic acid is employed. This circumftance is.very advan- tageous, and contributes to the obtaining a larger quantity of ether and {weet oil. ~ * Our ether does not, I believe, requireto be retified over fixed alkali, as is commonly done with vitriolic ether, in order to cleanfe it from any fuperabundant acid. ¢* This ether may be wathed in water, on the furface of which it fwims, while a white matter is precipitated. - It precipitates a {olution of filver into luna cornea ; which fhews its origin. ¢¢ Laftly, it is a very fingular and furprifing fad, that the fame mafs which remains dry at the bottom of the retort, and which ferved to make the ether, may be employed, again and again, without end, for the fame purpofe, and without addition of more flowers of zinc. For, by re-diffolving this mafs in {pirit of falt, and by filtrating, and re-diftilling with fpirit of wine, as was done the firft time, more and more ether will be obtained, and the mafs will never lofe its concentrative power,” Aay municated ETHER municated to the Academy in 1742, is very fimple, as it confifts only in mixing together fpirit of wine and fpirit of nitre in a bottle, which is to be exaltly clofed, and left at reft, till the ether is formed -and colleéted like an oil upon the furface of the liquor. This ether is made, as we fee, without diftillation. Since Mr. Navier has publithed his difcovery, other chemifts have endeavoured to improve the procefs.” A very good procefs is publifhed in the Encyclopedia, which is attributed to Mr. Rouelle. Mr. Beaumé alfo has publifhed one in his Differtation on Ether, which is very accurate, and is the refult of many trials and refearches. Mr. Beaumé’s procefs is as follows. : Put fix ounces of rectified fpirit of wine into a bottle made of ftrong and thick glafs, large enough to contain a pound of water. Place this bottle in a bucket of frefh water, which will be fill better for the purpofe, if it has been rendered colder by throwing into it two or three pounds of ice, in fmall bits. Pour upon the fpirit of wine, at four or five times, four ounces of fmoking fpirit of nitre, fo concentrated, that a phial, capable of contain- ing an ounce only of water, fhall be capable of containing an ounce and a half of this fpirit of nitre: obferving, during the whole time of pouring the fpirit of nitre, that the fpirit of wine be kept in a fate of perpetual rota- tion. As foon as the two liquors are mixed, ftop the bottle quickly with a good cork, which muft be driven firmly into the neck of the bottle, and covered and faftened with a piece of leather doubled, and bound with pack- thread. Leave it at reft in the cold water, which ought to be fometimes renewed. Two or three hours afterwards, the. liquor lofes fome of its tranfparency by the interpofition of many fmall drops of ether, which are difengaggd throughout the liquor. This ether gradually collects and floats upon the furface. With- in twenty-four hours the mixture will have beconie clear ; and the ether formed, which will be about two ounces, may be feparated. But as more ether will {till be produced, the method is to leave it feven or eight days before any of it be feparated. After this time no more ether is formed. Pierce then the cork with a pointed inftrument; and a confiderable quantity of air will efcape with a hiffing noife, which had difengaged itfclf during the production of the cther, and which is comprefled in the bottle. When the air has efcaped, uncork the bottle, and pour quickly Les . : . ) its ETHER its contents into a glafs funnel, that the ether may be feparated. | i The ether will amount te about four ounces, and the refiduum will weigh five ounces and a half; fo that half an ounce fhall have been loft during the procefs. This ether ought to be put into a well clofed cryftal-glafs bottle. (2) Nitrous ether in this ftate has a fmell like that of the vitriolic ether, but fomewhat ftronger and lefs agree- able. It has a light citron color; and as foon as the bottle which contains it is uncorked, it bubbles and effervelces, When the flopper is put in loofely into the neck of the bottle, it may be obferved to rife and fall alternately, which appearance is occafioned by vapors efcaping from the ether. he caufe of thefe phenomena is a confiderable quantity of air which remains interpofed betwixt the parts of ether ; for when all this air has been once difengaged from the ether, thefe phenomena do not happen. Nitrous ether is not, in this ftate, pure; as it retains fome of the acid employed, from which it may be purified by mixing it with fome fixed alkali, and rectifying it with a lamp-heat. In this re@ification, it fuffers a lofs of nearly one half its quantity. The properties of this rectified nitrous ether are, that jt burns with a more luminous flame than the flame of vitriolic ether; that this flame is accompanied with a more fenfible quantity of foot; that after the ether is burnt, a refiduum’ (t) Mr. Woulfe defcribes an apparatus by which nitrous ether may be expeditioufly obtained by diftillation with the heat only occafioned by mixing together the nitrous acid and the {pirit of wine. This diftillation is performed in a matrafs with a high neck, to which is fitted a head, with a {pout, communicating with the receiver by means of a long tube. The vapors that are not condenfed in this receiver, or in a bottle joined to a {pout in its bottom, are conveyed from the receiver through a bent tube into fpirit of wine contained in a bottle. If any vapors pafs uncondenfed through this fpirit of wine, they are conveyed through another bent tube into more {pirit of wine contained in another bottle. The liquor collefted in the bottle annexed to the receiver being flowly rectified with flaked lime, furnifhes very fine ether. The {pirit of wine in which the vapors were con- denfed, contains fo much ether, that this fluid may be feparated from the fpirit by adding water. This {pirit of wine is by the Operation changed into good dulcified fpirit of nitre. See z/e Fil, Tranf, wal, g. of ETHER of coal is perceptible; and, laftly, that if it be evaporated on the furface of water in open air, it leaves upon the water fome oil, as the vitriolic ether does, but in a little larger quantity. In other refpeéts, but in thefe which thew that the nitrous ether is of a more oily nature than the vitriolic, thefe two ethers are perfectly fimilar. The adtivity and violence with which nitrous acid as upon the {pirit of wine is the moft remarkable circumftance of this operation. The action of nitrous acid is fo much ftronger than that of vitriolic acid upon fpirit of wine, that equal parts of concentrated nitrous acid and {pirit of wine cannot be mixed and contained : for nowithanding all the precautions that can be taken to moderate the a&ion of thefe two liquors upon each other, they mix with fo much violence when that proportion is ufed, that the mix- ture is inftantly heated almoft to inflammation, is reduced to vapors, and burfts the veflels with a terrible explofion. In Mr. Beaumé’s Diflertation upon Ether, an account of the trials which he made upon this fubjeét, and of the refulting phenomena, may be feen. In the fecond place, when fpirit of wine and nitrous acid are mixed in proper proportions, ether may be obtained without diftillation ; which is peculiar to this acid. The effects peculiar to the nitrous acid, in the preparation of ether, are caufed by the altion which this acid has, not only on the watery principle, but alfo on the inflammable principle of the {pirit of wine. = We have therefore reafon to believe that nitrous acid converts {pirit of wine into ether, not only by depriving it of its watery principle, but alfo by ating upon its inflammable principle with which it combines, or to which perhaps it joins its own inflammable principle. This is fo true, that nitrous ether may be made with a nitrous acid which does not fmoke, and which is, in fome meafure, f{aturated with water. For this purpofe, a larger proportion of {pirit of wine ought to be added. But if nitrous acid converted fpirit of wine into ether, merely by depriving it of its Waery prin- ciple, a diluted acid ought not to have the fame eftect as a fmoking and concentrated acid, particularly as it cannot concentrate itfelf during the operation, fince this is per- formed without diftillation. Befides, as nitrous acid has a greater affinity than any other with the inflammable prin- ciple, and contains a greater quantity of it, we ought not to be furprized that nitrous ether is produced without diftillation, and more eafily than any other. Marine Taf? + Marine acid, on the contrary, having the leaft difpofition of all the acids to unite with the inflammable principe and feeming to contain lefs of it than any other acid "does therefore produce ether with moft difficulty; or ro erl fpeaking, does not produce any ether, when ee only when it has been combined with metallic fubffances as tin and antimony ; part of the phlogifton of which jt may have acquired. * See ETHER (MARINE). Tt probabl becomes: more proper to combine with the inflemmably principle of the fpirit of wine, or tb communicate that which it has received, after it has already begun to unite itfelf with the inflammable principle of metallic matters From thefe confiderations we are inclined to beljey that in the production of ether, the acids a& at the for fins upon the watery and inflammable principles of the foe or wine, by depriving this {pirit of the former, and th Suing purely with the latter; or by encreafing its propor of acid, and thereby approximating it to an oily All acids, and particular] mineral acid Bitacarions, and even pT Th re fo Heh ein a fufficient quantity of {pirit of wine I. Pott, 1n his Differtation on the fays, that this aci lofes the difagreeable fmell pec ui penetrating and agreeable {mel ; that it does not in opm of red vapors; but -that it rifes with a lefs decree Of heat than when pure, and that it ads Jefs powerfully on fixed alkalis and abforbent earths. He adds in diftilling this mixture, oil and a refiduous coal ma i obtained : and that if nitrous acid previoufly conte] with {pirit of wine be faturated with a fixed alkali. a falt is formed which does not detonate like nitre, but burns lik ou falt, without wafte or diminution. ? 118 Wig desing thinks, that this experiment may fuggeft : erning the tranfmutation of acids, and he be- leves that the nitrous acid, in that experiment, lofes it detonating and other effential qualities ; becaufe the Ro gifton which enters its compofition as a principle, is joined and confounded with the inflammable matter of fay {pirit of wine. The marine acid feems to fuffer lefs Tran in combining with fpirit of wine; for Mr. Pott fa = alf in his Differtation on the Vinous Acid of Salt oR faturated with an alkali fome marine acid, previoufly treated with fpirit of wine, he obtained a regenerated common fal, 2 which ETHILOPS which poflefled all the effential properties of common falt, Neverthelefs, Mr. Pott, having diftilled to drynefs the thick matter which remains after the moft fluid and volatile part had been diftilled from a mixture of marine acid and fpirit of wine, obtained a refiduous black fixed coal: which proves that one part of the acid of falt contralls in this experiment a very intimate union with the principles of fpirit of wine; for the igjne acid £04 {pirit of wine diftilled ertainly not leave any refiduum. : Ios M ARTIAL). Martial ethiops is iron divided into exceedingly fine parts by the aétion of water. ‘This preparation was introduced into medicine by the younger Lemeri, who called it ezhiops from its black color. I o make ethiops, filings of iron are taken, very clean and free from ruft, and are put into a glafs veflel ; on thefe pure water is to be poured, to the-height of three or four fingers thicknefs above the filings; the filings are to be frequently ftirred with a fpatula, till they become fo fine a powder, that when agitated they remain long fufpended in the water : the water, thus rendered turbid by the fufpended powder of iron, is to be decanted ; and the fediment which is depofited is to be dried and ground on a porphyry. This is the martial ethiops. , Iron is a metal which is foluble in many menftruums. Its furface is fenfibly affected by the combined action of air and water, and 1s in fome meafure corroded. It is thereby deprived of part of its inflammable principle, and partly reduced to an earth or calx, called ru/f: but to pro- duce this effe@, thefe two elements muft concur : for iron is not rufted nor altered by expofure to dry air, or to water alone, without contact of air. (z) Neverthelefs, the operation of ethiops martial {hows that water alone, without the concurrence of air, 1s capable of a certain ation upon iron ; fince this metal is, by this action continued fome time, reduced to parts exceedingly fmall, («) Iron is not fo readily rufted when kept immerfed in water, as when it is firft moiftened and then expofed to air; but it is neverthelefs fubje& to ruft if it be kept a few days under water, as thofe workmen know who have occafion frequently to keep pieces of iron under water, to foften and render the metal more duétile, and alfo to preferve the furface from ruft during a fhe time. When they have occafion to preferve iron from ii a longer time, they immerfe it in lime-water, which being free from gas, is not fo apt to ruft iron as other waters are. Whethes ET R1O0OPTS Whether this effet is caufed by fome heterogeneous par- ticles in the water or in the iron, has not yet been deter- mined. The iron thus reduced into martial ethiops is cer- tainly very different from ruft: It is black, attractable by magnets, and foluble in all acids; which proves that it is not deprived of its inflammable principle. Ruft, on the contrary, has none of thefe qualities. Thefe properties of martial ethiops have induced fome perfons to propofe it asa remedy much fuperior to other preparations of iron. This manner of preparing iron for medicinal purpofes is certainly good and unexceptionable ; but Mr. Lemeri certainly ought not to have declaimed againft all other preparations of iron indifcriminatel , nor to have advifed their total difufe in medicine. He pro- nounced this general profcription without fufficiently un- derftanding the matter. He would probably have been more indulgent, if he had known that feveral martial faffrons, fuch as thofe called aperitive, and which are no- thing but ruft, are capable of eafily refuming, and by the humid way all the phlogifton which is nece ary to reftore to them all the properties of martial ethiops ; and that this change is actually produced upon them when they are taken internally, by the fat matters which they meet in the ftomach, in the inteftines, and in the aliments and digeftive juices. This is proved by the blacknefs of the excrements of thofe who have taken thefe martial faf- froms.: Mr. Lemeri had certainly not examined the nature of the precipitates obtained from folutions of iron in acids, and particularly in the vitriolic and marine acids, by a phlogifticated alkali; for he muft have obferved, that fuch precipitates receive from the alkali a fufficient quantity of phlogifton to give it a dark and blackifh color, and to render it foluble in any acid: confequently thefe preci- pitates, which are at leaft as fine as the martial ethiops,, are alfo equal to it in folubility, and preferable from the greater facility of their preparation. When well phlogifticated precipitates are required, they ought to be dried in clofe veffels, and by diftillation. This, is an operation which is alfo neceflary for martial ethiops, although the author does not direct it; for the iron, being moift and much divided, rufts with the greatefk facility from the conta& of air. Martial ethiops, and the martial precipitates and faffrons sbeve-mentioned, are fuccefsfully employed in medicine as ETHA OP § as excellent tonic and fortifying remedies. See upon this fubjel? IRON. ETHIOPS MINERAL. Ethiops mineral isa com bination of mercury with a fufficiently large quantity of fulphur. The color of this compound is black, and hence it has been named ethiops. Ethiops mineral may be made either by fufion, or by trituration without fufion. To make ethiops mineral by fufion : To fulphur melted in an unvarnifhed earthen veflel, an equal quantity of very pure mercury is to be added ; the veflel is at the fame time to be taken from the fire, and the mixture is to be ftirred with a fpatula till it be cold and fixed ; the mixture is then become a black and friable mafs, which is to be pounded and fifted. This is ethiops. To make this preparation without fire, two parts of mercury are triturated in a glafs or marble mortar with three parts of flowers of fulphug till the mercury no longer appears. Mercury and fulphur have a ftrong difpofition to unite together. For this purpofe, their integrant parts muft be made to touch, and then they contraét an adhefion, but not fo ftrong as that which they acquire by fublimation in the proceis for making cinnabar. ‘The black color of ethiops is always taken by mercury, when it is much divided and mixed with inflammable matters. In this refpeét it refembles filver, lead, and other metals, which acquire a black color from the fuper- ficial union which they contract with fulphur or other phlogiftic matters. Although the union of mercury with fulphur in ethiops 1s not fo {trong as in cinnabar, we muft not believe that in ethiops thefe two fubftances are not united, but only mixed and interpofed ; for they really adhere and are combined together. "I'he proof of this is, that they cannot be feparated from each other without intermediate fubftances. Thefe fubftances are the fame as thofe which are capable of pro- curing a fimilar feparation by decompofing cinnabar. See CINNABAR. The difference betwixt ethiops prepared by fufion, and ethiops prepared by trituration is, that the former contains a lefs quantity of fulphur than the latter. Mr. Lemeri has obferved, in his Courfe of Chemiftry, that when ethiops is made with fire, one half of the fub- ftances employed is loft; but the proportion in which eae EVAPORATION each of the fubftances is diffipated is not known: we are however, certain, that more fulphur is loft than mercury ; notwithftanding which, each kind of ethiops contains more fulphur than is neceffary for the faturation of the mercury as evidently appears from the operation of making artifi- cial cinnabar. The chief ufe of ethiops mineral is in medicine. I¢ may be given from fix grains to half a dram, incorporated with other fuitable remedies. It is employed as a refolvent in the afthma, fcrophula, obftruGions and difeafes pro- ceeding from a ftoppage or thicknefs of humours. Some phyficians prefcribe it in venereal difeafes : others affirm that ethiops has no medicinal virtue : however, it certain] ; occafions falivation fometimes, although feldom. See Mac CURY. EVAPORATION. Evaporation is a chemical ope- ration, by which, with a certain degree of heat and accefs of air, volatile fubftances are feparated from others lefs volatile. The effect of evaporation is effentially the fame as that of diftillation, with this difference, that diftillation js almoft apays employed to pniae and collect a volatile fubftance 3 Whereas evaporation is always employed to fe : collect the fixed or lefs le Hr, WEI volatile part being neceflarily loft in the operation. Evaporation is always made in open air, and with open veflels ; for air contributes much to the volatilifation of bodies, and evaporation js only performed from their fur- faces : hence the general rules for evaporation are, to place the aay from which volatile parts are to be evaporated in a flat, fhallow, wide veflel, fo that it fhall prefent to the air a large furface, towards which even a current of air ought to be directed. In all €vaporations the degree of heat ought to be pro- portioned to the volatility of the fubftance to be evaporated and {till more to the degree of fixity of the fubftance in. tended to be left, and of its adhefion to the volatile parts. Thus, the lefs fixed the remaining fubftance is, and the more ftrongly it adheres to the volatile fubftance, the lefs the heat ought to be. For inftance, if we would obtain the portion of oil which is found jg rectified {pirit of wine and ether, thefe liquors ought to be evaporated, as Mr. Beaumé did, upon the furface of water in open air, and without any other heat than that of the atmofphere ; for however little the evaporation of thefe liquors is urged by a heat . EXCREMENTS ili his {mall ] hat too ftrong, the volatility of t : 2 how fb oil differs fo little from Shat Soisit of Vine that it would entirely exhale wi i < en any feparation, as it does when they i ified Thus M, . Duhamel having difcovered, by his - A that the volatile alkali of fal ammoniac carries ore it a confiderable portion ne fixe Sn io i d to difengage it, co termediate fubftances employe fo i 3 from the concrete vola afterwards feparate this earthy part ols i i a latter to diffipate itfelf by the tile alkali, but by allowing this Bel ae heat alone of the air, and by an evapora Eh eas | 1 months; becaufe this earthy part, g wi Ae is To well combined, and he fo fran So ! . . . . xr . ong w volatile alkali, that it is always carried a Spi i i whenever the heat exceeds tl fo ger Myr. Dubamel’s Memoirs concerning Sal Ammoniac among 1 the Memoirs of the Academy. i On the contrary, in fome cafes evaporation may urged by a ftrong heat, and ye by 2 isi To i he body. is is p directed upon the furface of the b $ : d is not very volatile, an when the part to be evaporated 1s r yeaa ii le heat to raife it, and when eS der fixed, and does not adhere much maining fubftance is very fixed, Se latile part. Such, for example, is ne csi oe antimony in the purification of gold by imony. See that operation. ag AP ok wn in evaporation are bafons, = crucibles ; and thefe veflels are made of glafs, metal, » 3 earth according to the nature of the bodies on which the 9 operation is to ron) EUPHORB VI. (x EXCREMENTS (LIQUID) o ANIMALS. EXCREMENTS (SOLID) of ANIMALS Alchemifts, who have fought every where for their great work, as they called it, have parsentarly Spefaiell Bed ents of men and other animals ; but philofo- hv ony has acquired no knowledge from all thes alchemical labors, from the obfcurity with which their i i refinous juice. EvpnorBiumMm is a very acrid, gummy, ic Fron an ounce of enphorbium five rime were WL Wi rere extracted b . and from another ounce five drams al 0 wer i Both thefe extraéts, but chiefly the fpirituous, were acrid an corrofive. Neuman thors EXPRESSION authors have -defcribed them. The philofophic chemifts have. not much examined animal excrements. Of thefe, Homberg is the only one who has particularly analyfed and examined human ordure ; and this was done to fatisfy an alchemical projet of one of his friends, who pretended that from this matter a white oil could be obtained, with- out fmell, and capable of fixing mercury into filver. The oil was found by Homberg, but mercury was not fixed by it. The labors of this able chemift were not however ufe- lefs, like thofe of the alchemifts, becaufe he has clear] related the experiments he made on this matter, in the Memoirs of the Academy of Sciences. Thefe experiments are curious, and teach feveral effential things concerning the nature of excrements. The refult of thefe experiments is as follows, Frefh human feeces, being diftilled to drynefs in a water- bath, furnifh a clear, watery, infipid liquor, of a difagree= able fmell, but which contains no volatile alkali ; which is a proof that this matter, although nearly in a putrefaétive ftate, is not however putrefied ; for alj fubftances reall putrid furnith with this degree of heat a manifeft volatile alkali. See PurreracTioN, The dry refiduum of the foregoing experiment, being diftilled in a retort with a graduated fire, furnifhes volatile alkaline fpirit and falt, a fetid oil, and leaves a refiduous coal. Thefe are the fame fubftances which are obtained from all animal matters, Sze SupsTaNncEs (ANIMAL). Human feeces, diluted and lixiviated in water, furnith by filtration and evaporation of the water an oily falt of nitrous nature, which deflagrates like ‘nitre upon ardent coals, and which inflames in clofe vefiels, when heated to a certain degree. This fame matter yielded to Homberg, who treated it by a compleat fermentation or putrefation, excited by a digef- tion during forty days in a gentle water-bath heat, and who afterwards diftifled it, an oil without color, and without bad fmell, and fuch as he endeavoured to find ; but which did not, as we faid ‘before, fix mercury into iver. : EXPRESSION. Expreflion is a mechanical opera- tion, by which the juices of many plants are obtained ; and fweet oils, which are not volatile, may be extradted from many fubftances in which they refide fuperabundantly and uncombined. Such ae all emulfive feeds, and fome Vor.I. fruits, EXTRACT fruits, as oranges, citrons, lemons, olives, &c. An oil may, alfo be obtained from yolks of eggs by expreffion. his operation is performed by putting the fubftance to be exprefled, previoufly bruifed, in a machine called a prefs. The plants from which the juices are to be extraéted, having been bruifed in a mortar, ought to be wrapped up in a ftrong and clofely woven linen cloth, and then put into the prefs. The plants which are not very fucculent, or too mucilaginous to give their juices by expreflion, ought to be mixed with fome water when they are bruifed in a mortar. Grains or feeds muft alfo be bruifed before they are ex- prefled to obtain their oil, fo as to form them into a greafy pafte, the oil of which exfudes {fpontaneoufly. They are then to be wrapped in a ftrong linen cloth, and exprefled. "Fo obtain as much oil as is poflible, this pafte ought to be exprefled betwixt two hot iron plates. But this method renders oils rancid, and therefore ought not to be ufed in the preparation of oils for medicinal purpofes. To obtain oil from yolks of eggs by expreflion, they ought previoufly to be hardened by baking, or even a flight torrefaction. See Juices (EXPRESSED), and O1Ls (SWEET). EXTRACT. This word, taken in the moft general fenfe of which it is capable, is applicable ‘to fubftances feparated from any compound body by a proper menftruum. But it is generally confined to denote fubftances feparated from vegetables by water. ; To make an extra from any vegetable fubftance, it muft be infufed or boiled in a fufficient quantity of water, to ex- tra@ from it all the fubftances foluble in this menftruum. If the vegetable matter of which the extra& is to be made is itfelf fucculent and watery, it need not then be infufed or boiled. The juice which contains all the nratter of the extra may be exprefled ; for in this cafe, the water in the plant has the fame effect as the water employed in in- fufion or decoction. Then the infufion, deco@ion, or exprefled juice of the plant muft be evaporated till the acquire more or lefs firm confiftence. For fome extiadts are made as foft as pafte, and are called [oft extralls; others are evaporated till ney become dry, and are called dry or Jalid extracls. he liquor from which the extract is to be made by lefs charged with feculent evaporation is always more or 9 ; hich ‘render it turbid, be- matters, earthy or refinous, w caufe thefe matters are not foluble in water. ‘Thefe matters are generally feparated before the liquor is eva- : porated EXTRACT porated to the confiftence of an extrac, which may be done by clarification with the white of an egg, or other- wife. By this pation of feculent matter, foft extralts are rendered lefs liable to ferment and to become mouldy. But as the intention of making an extra& is to preferve all that can be preferyed of the principles of plants, the fiquor of the extra Sught not to be clarified, but it ought 0 be evaporated till it bec c hn 2p wand Wl t f omes dry, and thereby rendered As extracts hi) to refemble, as nearly as is poffible the vegetables from which they are obtained, they ought to be evaporated with a gentle heat, and in a water-bath; becaufe the delicate and compounded principles of vege- tables are liable to be changed by a firang heat. But to avoid the inconveniences attending a tedious evaporation by which a fermentation of the matter might be induced, this evaporation may be accelerated by encreafing the fur. face of the liquor, which therefore ought to be diftributed in many flat and wide-mouthed veflels. Se Evarora- TION. In this manner the Count de la Garaye prepared what he called ¢ffential falts, which are nothing but folid extracts, the beft and moft perfe& which can be obtained. From what has been faid concerning extracts, we ma conclude, that they are colleGtions of the proximate i ciples of vegetables, and chiefly of thofe which are foluble in water, and which are not fo volatile as to be capable of diffipation by the heat of boiling water. They contain; therefore, when well made, all the gummy, mucilaginous, faponaceous, (that is, the oil rendered foluble in water by fome faline fubftance) bitter, or faccharine matters; a laftly, all the eflential falts, acid or others, or any other faline matters, which are contained in vegetables. In well made extracts are alfo found portions of the oil refinous, and earthy principles of vegetables, which, although infoluble in water, have been extracted along with the other principles into the juice, infufion, or de- coltion ; excepting, for particular reafons, thefe principles are required to be excluded. If exttacts are required which fhall poflefs as much as they can of the properties and virtues of plants, we ought not only to extraét by water Bus alle by {pirit ox wige, and to mix together the fuub- e us extracte thefe t Andras by Mrrsratons, » Reaangs, be e tafte of almoft all extralls is bitter or fali fomewhat like that which fugar or other ns Fei Bb2 ftances | rEEEty frances acquire by flight burning. But this latter quality is faulty. g It from a too ftrong heat having been employed to evaporate the extra&ts, by which fome of the fubftances contained in the extra are confiderably changed, deftroyed. o Sorrel dry ertrolls, or eflential falts of the Count de la Garaye, attra& moifture from the air, and even become Nouid, This property is occafioned by a feparation of the {aline from the refinous and earthy parts of the vegetable, and which are therefore uncombined, and confequently apt & moifture.’ 2 Thefe J ought to be preferved in well clofed bo 'RACT (MARTIAL). “This name is given to a pharmaceutical preparation, which is not, properly fpeaking, an extradt, fince it is only a combination of iron with tartar, called Tinéture of Mars, reduced to the con- fiftence of an extrac. See TINCTURE of MARS. ALSE GALENA. This is a mineral which re- fembles at firft view the lead ore called galena; but hich no metal is extracted. ro LSE PRECIPITATE. This name is given to a matter which has the appearance of a precipitate, but which has not been feparated from a menftruum. Such is Farse GarLena. Pleudo Galena, called alfo Black-jack, or 3) is an ore of zinc, containing, befides that femi-metal, generally fome iron, together with the mineralizing {ubftances fulphur and arfenic, It is frequently intermixed with the lead ore called galena, and fometimes with the cupreous pyrites. In England the former kind is found in the lead mines of Derby- fhire, and the latter in the copper mines of Cornwall. This mineral, formerly negleéted as ufelefs, has lately been employed, after a careful calcination, inftead of calamine, for the manufac- ture of brafs ; and might alfo be employed as calamine 1s, for the extra®ion of zinc. For thefe purpofes, that kind of blend 1s fitteft which contains moft zinc, and leaft of iron and arfenic. Such is the blend of Derbyhire, which is a very rich ore of zinc. This kind is more laminated in its texture, and of a greyifh color when fcratched ; whereas the blend found in Cornwall has a more teffelated texture, confifting of oblong parallellipipedons, is of a reddifh color when fcratched, and contains a larger quan- tity of iron and arfenig, mercury B.A T mercury reduced into a red powder without addition, and merely by heat, improperly called precipitate per fe, or mercury precipitated by itfelf : fuch alfo is red precipitate, which is mercury diffolved in fpirit of nitre, and after- wards deprived of moft of the acid by fire, without any intermediate fubftance. Silver, lead, mercury, feparated from nitrous acid by marine or vitriolic acids or falts, are alfo generally confidered as precipitates, and are really fo, as they are aGually feparated from one fubftance by the intervention of another: but as this feparation is made by the union of the precipitated metal with the precipitating acid, fuch precipitate ought to be diftinguifhed from thofe which are nothing but the precipitated matter uncom- bined and fingle. §ee PRECIPITATES and PRECIPITA- TION. _ FAT. Fat is an oily concrete fubftance, depofited in different parts of animal bodies. To obtain fat very pure, it muft be cut into pieces, and cleaned from the interpofed membranes and veflels ; it muft then be cleanfed from its gelatinous matter by wathing with water, till the water comes from it colorlefs and ine fipid ; it is afterwards to be melted with a moderate heat, in a proper veflel, with a little water; and it is to be kept thus melted till the water be entirely evaporated, which is known by the difcontinuance of the boiling, which is caufed by the water only, and which lafts till not a drop of it remains: it is afterwards to be put into an earthen pot, where it fixes; then it is exceedingly white, fuffi- ciently pure for the purpofes of pharmacy or chemical examination. Fat thus purified has very little tafte, and a weak, but peculiar fmell. Mineral acids exhibit the fame phenomena with fat, as they do with the fixed {weet oils of vegetables, which con- tain nothing gummy or refinous, and which do not dry. Such is the oil of ben, oil of olives, and all thofe which chemifts call fat oils. Alkalis diflolve fat, as they do thefe oils, and form a fimilar foap, Fat contains no principle fo volatile as to be raifed with the heat of boiling water. It does not inflame but when heated in open air fo as to rife in vapors. Latitly, by age it contrats an acrid and rancid quality. hen fat is diftilled with a heat fuperior to that of boil- ing water, which muft therefore be done in a retart, and in a naked fire, firft an acid phlegm arifes, and a fmall por- Bb 3 tion FAT tion of oil which remains fluid. As the diftillation con- tinues, the acid becomes ftronger, and the oil thicker, and at laft it congeals in the receiver. No other principle arifes during this diftillation : and Ll, when the retort is i nothing remains but a very fmall quantity of that kind of ccal which cannot be burnt without very great difficulty. See CoaL. ; : ; If - the congealed oil which is found in the receiver be again diftilled, more acid 1s obtained, -and an oil which does not congeal ; and thus, by reposting the diftillations, the oil is more and more attenuated, hile it is thus deprived of its acid, it acquires a more and more pene- trating fmel; and thus by diftillation alone it may be rendered as volatile as effential oils, and capable of rifing with the heat of boiling water. di " From all thefe, properties of fat we may perceive It is 2 fweet concrete oil; not volatile, and perfectly analogous to butter and wax; and that its confiftence, as well as the confiftence of thefe analogous fubftances, is caufed by an acid intimately united with it, which cannot be feparated but gradually and by repeated diftillations. Fat, and all other analogous oily matters, cannot be heated fufficiently to be raifed into vapors, without fuffering a confiderable alteration, and even decompofition. The vapors which rife from it, when heated in open air, are the fame as thofe which rife when diftilled in clofe veffels, They confift of acid and attenuated oil. This acid is remarkably pene- trating, acrid, and volatile ; it irritates and inflames the eyes, the throat, and lungs; it makes the eyes fhed tears, and ‘excites a cough as much as volatile fulphureous acid does, although its nature be very different. When fat is in its natural ftate, and has not yet fuffered any alteration, its acid is fo well combined with its oily part, that none of its properties.can be perceived, Thus fat in good condition is very mild, and ufed focsfefully in medicine, particularly externally, for its lenient quality but, .notwithftanding its great mildnefs, before it has been heated fufficiently to decompofe it, and while it is yet freth, it becomes exceedingly acrid, irritating, ahd cauftic, when its acid is partly difengaged by fire or by time. "When fat is become very rancid, not only its medicinal effects, but alfo many of its eflential properties, are totally changed, particularly its property of refifting’ the action of fpirit of wine: for this menftruum, . which does not affect pure and unchanged fat, diflolves fome portion = F.A T fat which has been ftrongly heated, or which. has become rancid. This effe& can certainly proceed from no other caufe, than that the acid of the fat difengages itfelf in both thefe cafes. Mr. Macquer has fhewn this in his Memoir. concerning the Caufe of the different Solubility of Oils in Spirit of Wine. We fhall {peak more fully on this matter at the article OiL. Mr. De Machy, an intelligent apothecary of Paris, and an able clic oil and obferver, has made a remark upon this fubjet which correfponds with this opinion; which is, that all the rancidity of fat may be taken from it by treating it with fpirit of wine. Now, this evidently happens, becaufe the {pirit of wine diffolves all the portion of fat which is dif- engaged from its acid ; that is, all the rancid part, while it does not touch that which is not changed. This practice may be advantageoufly employed for the prefervation or recovery of fome fats ufed in medicine, but which are rare, and not to be procured in their recent ftate. The decompofition of fat, from which may be obtained acid, oil, a very fmall quantity of refiduous coal, and not a particle of volatile alkali, proves evidently, that this fubftance, although elaborated in animal bodies, of which it makes a part, has not the marks of an animalifed matter; it therefore feems to make a feparate clafs, and to be pro- duced from the oily parts of the aliments which could not enter into the compofition of the nutritive juices: it is confequently an oil fuperabundant to nutrition, which nature depolfites and referves for particular purpofes. One of the chief ufes of fat probably is to receive into its com- pofition, to blunt and correct a great part of the acids of the aliments, and which are more than are requifite to the compofition of the nutritive juice, or which nature could not otherwife expel. This is certain, that the greater the quantity of aliments is taken by healthy animals, above what is neceffary for their nourithment and reproduction, the fatter they become. Hence animals which are caftrated, which are not much exercifed, or which are come to an age when the lofs and production of the feminal fluid is lefs, and which, at the fame time, confume much {ucculent aliment, generally become fatter, and fometimes exceed- ingly fo. Although fat be very different from truly animalifed fubftances, and appears not eafily convertible into nutritive juices, it being generally difficult of digeftion, and apt to become rancid, as butter does in the ftomachs of many Bbs perfons ; FERMENTATION ‘perfons; yet in certain cafes it ferves to the nourifhment and reparation of the body. Animals certainly become lean, and live upon their fat, when they have too little food, and when they have difeafes which prevent digeftion and production of the nutritive juice ; and in thefe cafes the fatter animals hold out longer than the leaner. ‘The fat appears to be then abforbed by the veflels defigned for this ufe, and to be transformed into nutritive juice. The fats of different animals differ little. They have all the fame eflential properties, and only vary fenfibly in con- fiftence. Frugivorous animals, and particularly {heep, haye very firm fat; moft reptiles, and ‘particularly fifth, which are almoft all carnivorous, have a foft and fome- times a liquid fat. Sec BUTTER, Wax, and Ou. FEATHERS. (2) FENNEL. (a) FENUGREEK. (2) FERMENT. A ferment is a fubftance actually fer- menting, or ftrongly difpofed to ferment, and which is employed to be why, i The firft portions of liquors which pafs in filtration are almoft always more or lefs turbid ; wherefore they ought to be poured again upon the filter, and even more than once till it pafles perfectly clear. This happens becaufe the pores of the filter, at firft too open, are afterwards con- tracted by the fwelling occafioned by the liquor, or they are patly ftopped up by the fediment ‘which is depofited upon F IRE. Chemifts confider fire, as alfo the other ele- ments, in two vy different views: firft, as it enters into the compofition of many bodies, of which it i inci chit is apr or conftituent part; and fecondly, as being pure, pn ghsering into any compound, but acting fenfibly and ftrong- y upon all natural bodies, and producing ‘effe@s as a powerful agent in all chemical operations. In this latter eins of view we fhall confider fire in this article. It wis . confidered as a principle under the article PuLo= Pure, free, uncombined fire feems to b i ure, e a collet particles, the matter of which is fimple, ion a entirely unalterable. All the properties of this element ew that its particles are infinitely fmall, have no fenfible adhefion FIL. RE adhefion €6 each other, and that they have 2 very rapid, continual motion in all dire&ions, which is eflential to them. : gj this definition, fire appears to be a body effentially fluid, and many faéts concur to prove that it 1s the only body effentially fluid, confequently the caufe of the fluidity of other bodics ; and that as’ it alone counterbalances the general tendency of all the other parts of matter towards each other, they are prevented by it from uniting Into one immenfe, homogeneous, and perfeétly bard mafs. Whence can fo aftonifhing a difference proceed between the properties of the primitive Hoeprant molecules of po and thofe of the integrant parts of all other matter? Is fire then not material, or not compofed of matter, as its properties have induced fome philofophers to think ? Is it matter of a peculiar kind ? Or does, as a great geometri- cian thinks; the attra&ion of the parts of matter Seco negative, and changed into repulfion, when thefe parts become infinitely fmall, and can come infinitely near to each other; which feems very probably to be the cafe with i fire ? : ito Ge fa&s enough to decide corcerning thefe different opinions. We fhall, therefore, confine ourfelves to inveftigate the effential propertics of fire, chiefly Ho which influence moft in chemical operations. and chemic omena. PE ine can with great facility penetrate, OF fPiavaie itfelf from, any body however denfe; that is, any body w aaeres may be heated by expofure fo fire 5 or Se » its former e. by removing it from this eXpoiutc. gi Tonge Het we RS infer the infinite fief o the integrant parts of fire; and we may perceive the caufe on its equal diftribution through all bodies, when it is 2 e- termined by fome peticalas caufe to penetrate one body in ntity than another. : Fe { ibftances whatever, which are placed in any given degree of heat, and obliged to remain there, Sains precifely the fame degree of neat. This faét Das = afcertained by inftruments fit for meafuring the degrees of heat. ; ich the fire produces, or rather heate Ti A ore Fe fations of heat and light ; ¢ excited but when the fire is ina contains a certain body which is bodies, upon our fenfes, but thefe fenfations are no certain quantity ; for every known body portion of uncombined fire, and yet not any \ "FIRE is not lighted or ftro gly heated, excites in us any fenfation of heat or light. Befides, in certain circumftances, abo may appear luminous, although it has no more {enfible heat than the furrounding bodies. This is proved by the effe@s of feveral phofphoric bodies, fuch as the fcales of fith, rotten wood, glow-worms ; all which fhine in the dark, although no more heated than the furrounding bodies. Alfo certain fubftances may be fo penetrated with free and ative fire, as to excite fenfations of heat, and even to “burn, although they do not appear luminous even in the dark. Amongft thefe fubftances are ftones, metals, and even water, all which may be fo heated as to excite pain to perfons touching them, although they are not lumi- nous. Hence we ought to conclude, that the fenfations of heat and light are in many cafes infufficient to prove the pre- fence of any given quantity of fire in bodies. ; We ought alfo to remark, that although all bodies penetrated with much fire are neceffarily hot and luminous; heat, and not light, is the only certain fign of the prefence of fire. The reafon of this is, that bodies may be very luminous, without any change being induced into any of their effential qualities in thefe two contrary ftates; whereas the difference of more or lefs heat produces in all bodies alterations of their properties very fenfible and proportion- able to the difference of heat. Thefe confiderations feem to have induced fome philo- fophers to imagine, that light is a being which is indeed rendered fenfible by fire, but diftin& and different from it. According to this opinion, heat is only a property of fire ; whereas light is a diftin& and independant fubftance. This opinion appears to be even demontftrated, when we confider that light mye decompofed by refraction, as Newton’s experiments fhew; and that it is not, as pure fire is, capable of pervading all bodies, is proved by the opacity of many bodies, and by the reflexion of light. However that may be, a$ heat occafions more or lefs fenfible changes in the qualities of all bodies; and as its whole ation by which it influences any body confifts in the fingle quality, or, to {peak more accurately, the effential fluidity of fire, of which heat is only an effe®; we ought here only to confider the general effecis pro- duced by fire upon all bodies by heating them more or fefs. Thefe ant EE I A Sta pe Se 3 a Re Ning on rr - — Ps te AO I Ta rs PRG TLL a - . . bo" — pr Jn le 1 Sw a pe ii ke BoC a i aE EAE Bt ; eo FIRE Thefe- effeds, although diverfified, depend neverthelefs- on one principle and primary change produced upon all bodies, by which they are rarefied or made to occupy a larger fpace. In fact, every folid and fluid body, when penetrated by a greater or lefs quantity of difengaged fire, is more or lefs encreafed or diminifhed in fize than it was before. “This principle has fuggefted to philofophers feveral different inftruments by which this dilatation of heated bodies, or rather the heat which is the caufe of it, may be meafured ; and quantities of fire, too fmall to be eftimated by our fenfes, may be appreciated. The chief of thefe. inftruments is the THERMOMETER ; which Jee. As bodies are dilated by fire, their fpecific gravity muft confequently be diminifthed, and the adhefion of their in- tegrant parts muft alfo be diminithed. See AGGREGA- Ti0oN, INTEGRANT PARTS, and GRAVITY. Thefe two great effects, produced by fire upon all bodies, are the moft important and moft neceffary to be confidered, relatively to chemiftry. We may indeed fay, that they are the only effets; for excepting combuftion, which is a peculiar property of inflammable bodies, every chemical operation is performed either by a diminution of fpecific gravity, or by a greater or lefs disjunction of the integrant parts of bodies, as we fhall fee. Some fubftances are capable of a greater dilatation or diminution of their fpecific gravity, than others, by fire. Thus certain matters are fo much rarefied by even a mode- rate heat, that they feem to lofe all their fpecific gravity, or become at leaft fpecifically lighter than all the furround- ing bodies : hence thefe fubftances, when heated to a cer- tain degree, are raifed as bodies would be without gravity. All fubftances which have this property are called in general wolatile fubflances, See VoraTiLiTY. Other bodies are fo little dilatable by fire, relatively to their denfity, that the reateft -heat that can be given to them produces an almoft infenfible diminution of fpecific gravity. Thefe are called, from their being almoft unalterable in this refpect by fire, fixed bodies. See F1x1TY. : Hence, if we expofe to fire a compound body contain- ing fome fixed and fome volatile principles,’ the latter becoming fpecifically lighter ought to rife in'vapors, and to feparate themfelves from the former, which are unalter- able in this refpe&. But as almoft all compounds contain principles differing fo much in volatility and fixity, hii ome FRE fome of them may be raifed and fublimed, while others fhall remain fixed with fome given degree of heat; we may therefore, by heat alone, make many analyfes and decom- pofitions. If, for example, we expofe a compound of regulus of antimony, which is a volatile femi-mnetal, and of gold, which is a fixed metal, to a heat fo ftrong that the volatility of the regulus of antimony fhall take place; then this femi-metal, being raifed by its acquired levity, will be fublimed in vapors, and will be feparated from the gold, which will remain fixed and pure. See DISTILLATION, SUBLIMATION, EVAPORATION. The obfervation we have juft made concerning the changes in ‘the fpecific gravity of bodies, which the dilata- tion occafioned by heat produces, ought alfo to be applied to the diminution of the adhefion of their integrant parts, which is dn effet of the fame caufe; for if a body be dilated by heat, the contiguity, and confequently the adhefion, of its integrant parts muft be diminifhed : but in this refpet the feveral natural fubftances differ very much; for the integrant parts of fome bodies, when dilated by heat, are fo feparated and disjoined, that they feem no longer to cohere. If thefe bodies be naturally folid, they become fluid when they are penetrated with a fufficient quan- tity of difengdged fire, and are called fufible bodies. Thofe bodies, the integrant parts of which cannot be entirely dif- joined by fire, are called infufible or refratory : but as the aggregation of a body is broken when it is fufed, and as this deftruction of aggregation is a neceflary condition for the combination of bodies with each’ other; fire therefore, by rendering folid bodies liquid, has influénce as a principal agent in all combinations. Sec CoMBINATIONS, SoLu- TIONS, FusiBILiTy, and REFRACTORY. As all chemical operations may be reduced to decompo- fitions and combinations, fire is therefore in chemiftry, as in nature, an univerfal agent. Thus we know that, although decompofitions and analyfes may be made by men- ftruums without any more than the natural Heat, yet as thefe menftruums can only a&t when rendered fufficienth fluid by heat, fire therefore alts in thefe analyfes as eect, farily as in thofe which are occafioned by the immediate application of heat. : We ought to obferve concerning this fubjeét of the vola- tility, fixity, fufibility and infufibility of bodies, firft, that all’ thefe qualities are properly only relative. Not an ii is entirely fixed and infufible; and thofe which we or. I. Cc confider , EL. RE confider as fuch would .be reduced into vapors; as volatile bodies are, if they were expofed to a heat infinitely ftronger than any we can excite, Thus a body will appear fixed, or infufible, when compared with other very volatile and very fufible fubftahces; while it hall be confidered as vola- tile or fufible, when compared with others more fixed and lefs fufible. : In the fecond place, as volatility and fufibility are effects of one and the fame caufe, namely, of the dilatation occafioned by the prefence of a certain quantity of uncombined fire in bo- dies, thefe two qualities are properly the fame, in more or lefs eminent degrees ; and in this fenfe, volatility ought only to be confidered as the higheft degree of fufibility. lr, fubftances which are habitually liquid, and which ought therefore to be confidered as 2 moft fiifible, are all very volatile, and may be raifed into vapors with very little heat ; while, on the contrary, matters that are hard, and not very dilatable ; thofe, in fhort, the aggregation of whofe parts is the firmeft and moft difficultly to be broken, and which are therefore the leaft fufible, are alfo the moft fixed, The aggregation of all bodies, when reduced into vapors or fufed, is broken ; but more fo when reduced into vapors, than when merely fufed. Accordingly, the moft effectual of all methods for combining fubftances which cannot be eafily united, or which cannot be joined while the aggre- gation of one of them is fenfibly preferved, is, if pofiibls, to reduce them into vapors, and to make thefe vapors meet. All the effects which fire produces, as an agent in che- mical operations, are reducible, as we fee, to thofe we have mentioned. ‘The quantity of uncombined fire which flows perpetually from the fun, and diffufes itfelf through all its fphere, 1s fufficient to produce all the feparations and combinations which we daily fee effected by nature: but as the heat caufed by the fun is very limited, chemiftry would be confined almoft to the contemplation of natural operations, if we had not methods by which pure and un- combined fire may be made to enter bodies, or to quit them in greater or lefs quantities. The methods of encreafing the quantity or the activity of uncombined fire in bodies, may be comprehended in the following three: : Firft, by concave mirrors and by convex glafles, 2 num~ ber of thé rays of the fun, proportionate to the fize and good quality of the inftruments, may be collected into one F 1'R"E one point, called the focus. Bodies expofed to fuch a focus are penetrated with an infinitely greater quantity of uncom- ~ bined and alive fire than they have naturally. They are then ignited, inflamed, dilated, fufed, or volatilifed, ac- cording to their particular natures. The heat of fuch a focus is the greateft that art has produced. It is even ex- ceedingly too ftrong for moft chemical operations, and ought to be applied to the moft fixed and refractory bodies only. As fuch a focus is alfo very fmall and inconvenient for the performance of any operation, and as large mirrors and lenfes are very rare and dear, this fire is not much ufed for chemical operations. Neverthelefs, feveral very important chemical experiments were performed by colleét- ed folar heat ; as the decompofition of gold, publifhed by Homberg, if it be true; the fufion of platina, by Mefirs. Macquer and Beaumé ; and of feveral other bodies which could not be fufed by other fires, without addition of other fubftances, by other chemifts, at different times. : Secondly, experience has long ago taught us, and even the moft ignorant nations know, that heat and all the effets of fire may be occafioned by fri¢tion and per- cuffion of hard bodies. The heat excited by this method may be very confiderable, and even comparable to that of collected folar fire. It is in general proportionable to the force, rapidity, intenfity of friction and of percuffion, and to the hardnefs of the bodies rubbed or ftruck. This heat is alfo not much ufed in chemical operations : it, however, frequently occurs in many chemical’ experiments, as in fermentations, effervefcences, and folutions. It occurs whenever bodies unjte together ; and is proportionable to the rapidity and force with which they a& upon each other. It is produced by the friction and collifion of their inte- grant parts ; which thews, that the primary integrant parts are exceedingly hard, even 1n bodies generally foft or fluid ; for thefe fubftances, when diflolving, produce as much heat as thofe which are moft hard, and whofe: ag- gregation is moft firm. BA ¥ The third caufe which produces or excites heat is the combuftion of compound bodies, in the combination of which fire enters as an element or principle, and which are therefore called inflammable or combuftible bodies. The principal phenomenon prefented by thefe bodies is, that by mere contact with any other body, inflammable or not, but which is. ignited, they are kindled, inflamed, give much heat and light ; ina word, produce all the fame Cca efteéts F-1.X.1.7;. Y effets as the collected folar heat, or the allifions of bard bodies. This continues till the whole fubftance of fire, which entered into their compofition, and which was inac- tive, has refumed all the a&ivity of pure and uncombined fire, and is entirely diffipated. This inflammation of combuftible bodies is undoubtedly one of the greateft and moft aftonithing phenomena of na- ture : but it is alfo one of the moft difficult to be conceived. We cannot expect to underftand it well, till we know, better than we do at prefent, the effen-e and true ftate of fire when combined, and conftituting a principle of the bodies containing it, called phlogifion. See PHLOGISTON. We muft obferve at prefent, that as the combuftion of inflammable bodies produces all the effets of fire, pure, uncombined, and active; it is alfo the moft convenient method by which fire can be applied by chemifts to fe- veral bodies. The moft common inflammable {fubftances, fuch as wood, foffil coal, charcoal, are moft generally employed in che- miftry, in the arts, and in the ordinary purpofes of life, in all operations.where fire is requifite. | As chemifts have occafion to employ all the feveral de- grees of heat, from the weakeft to the {trongeft, they have difcovered methods of applying any required degree through intermediate fubftances, and ftill better by the difpofition and conftruétion of furnaces, in which the combuftible matters, and thofe to which the fire is intended to be ap- plied, are contained. See upon this fubject Baths, CoM- BUSTION, FURNACES. FISH. (¢) FIXITY. Fixity is a property, by which a body re- fifts the ac&ion of fire, without being raifed and diffipated in vapors. It is the oppofite quality to volatility. ~The degree of refiftance which a body ought to give tO fire, to entitle it to the character of being fixed, is not determined. Thus fubftances are confidered to be fixed almoft always relatively to others which are lefs fixed. (c) Fisu. Neuman obtained from fixteen ounces of fifh ana- lyfed by diftillation, thirteen ounces two drams and 2 half of vo- Jatile alkaline {pirit, five drams of concrete falt, three drams of oil, and an ounce four drams and a half of refiduum, from which, by calcination and elixation, twenty-five grains of faline matter were extralted. ‘The proportion of volatile falt thus obtained from fh is confiderably greater than that from flefh. | As f1LY AME As we do not know the ultimate degrees of the a&ivity of fire, we cannot fay whether any bodies in nature be capable of refifting ‘this extreme degree of fire without fublimation, or be abfolutely fixed. Thofe fubftances, however, are generally confidered by chemifts as abfolutely fixed, which lofe nothing of their quantity by expofure to the moft intenfe heat which they can produce. ‘The purcft and fimpleft earthy principle is 2 fubftance of this kind, and is perhaps the only one which can be confidered as naturally fixed, and is the principle of fixity of all the reft. Chemifts commonly call many fubftances fixed, which do not deferve that name, but comparatively with others, as we have already mentioned. In this fenfe, for inftance, vitriolic acid is fometimes called a fixed acid, by which is only meant that it is lefs volatile than others. For the fame reafon, regulus of antimony, and other femi-metals, may be confidered as fixed fubftances when compared with effential oils and ether, particularly in operations where they remain fixed, when expofed to a heat fufficient to evaporate effential oils or ether ; whereas thefe femi-metals may be confidered-as volatile, when compared with metals properly fo called. The fixity of bodies feems certainly. to proceed from their little dilatability by fire; and this defe& of dilatability is occafioned by the attraction or adhefion of the integrant parts of thefe bodies. See FiRE and VOLATILITY. FLAME. Flame is a colleftion of vapors of com- ‘buftible bodies actually burning, and which are themfelves in the motion of combuftion. (d) As @ Frame is generally faid to be an ignited vapor, or red- m hot {fmoke. Neverthelefs, Flame, Vapor, and Smoke, are things ditin& from each other, and ought not to be confounded toge- ther. We fhall endeavour to defcribe and diftinguith thefe : and firtt, of Vapor. By the action of certain determinate degrees of heat, with or without accéfs of air, all liquid and fome concrete bodies are fo dilated, as to occupy a much larger {pace than before this expo- {ure to thefe determinate degrees of heat ; acquire a confiderable expanfive power, or elafiicity ; and become tranfparent and in- vifible. They are then properly vapofs. This ftate they retain while expofed to the fame heat by which it was produced ; but by application of cold, they are condenfible into palpable fub- ftances, fimilar to thofe from which they were formed, if they hap- Cc 3 pened FLA ME i As bodies cannot burn but by touching immediately, thi air, and as for this reafon they only burn at their furface, flame, which is the only truly burning part of bodies which appear in actual combuftion, is always at their furface. It is luminous and ardent throughout its whole thicknefs, be- caufe it is only a mafs of adjacent; but difunited inflam- mable pened to confift of homogeneal parts, as water and mercury do ; or they are condenfible into palpable fubftances which are the confti- tuent parts of the bodies fubjeted to heat, if thefe bodies hap- pened to confift of parts not homogeneal, as plants do of water and effential oil. If the vapor confifts of inflammable parts, it may be kindled by contact with any ignited body; by which means, to- Ye with accefs of air or nitrous acid, it may be made to un- ergo thofe effects which are produced upon all bodies during their combuftion, namely, the decompofition of its parts, the dif- fipation of its phiogifton, and emiffion of heat and light : bat va- por thus ignited, rendered vifible, and in the at of combuftion, by accefs of air, or nitrous acid, is flame. This flame, or vapor decompofing by combuftion, is not condenfible, as we may eafily conceive, into fuch palpable fubftances as the undecompofed va- por is; but into fome only of the conftituent parts of thefe {ub- ances, the reft being altered by the combuftion. Thus the vapor of fpirit of wine is again condenfible into {pirit of wine ; but from the flame of fpirit of wine little can be obtained by condenfation but the water, which was one of the conftituent parts of that {pirit ; the other parts, efpecially the phlogifton, being deftroyed by the combuftion, that is, combined with the air which affifted the inflammation. Not only the vapor of an inflammable body, but alfo the inflam. mable body itfelf, without being previoufly changed into vapor, fay by contatt with an ignited body, or any other mode of applica- tion of heat, as friction, percuffion, &c. together with accefs 0 airor nitrous acid, emit a flame, which confifts, as in the former cafe, of particles flying off from that body inthe a& of combuftion. Thus, by applying a hot iron to {ulphur, we may {ee a lame immediately pro- duced upon the furface of the fulphur, We may eafily conceive that bodies thus kindled can only flame at their furfaces, becaule there only they are contiguous to air : but when nitre is intimate- ly mixed with the inflammable fubftance, as in gun-powder, the whole fubftance, its interior as well as ils exterior parts are in- ftantly inflamed ; becaufe the nitrous acid has, like air, the pro- perty of maintaining combuftion. Hence alfo we may eafily con- ceive why the external furface of a flame, by being contiguous with air, is much hotter than its internal parts, as may eafily be fhewn by applying any fubftance, alterable by heat, alternately to the exterior and interior parts of the flame of a candle ; and when FE A'M FE nable parts, which, touching the air on every fide, burn altogether and throughout their whole fubftance. No combuftible body really burns without flame. Thofe, indeed, whofe inflammable principle is firmly united with a great quantity of incombuftible matter, fuch as charcoal or afhes almoft entirely burnt, and moft metals, feem to be confumed without fenfible flame ; but this appearance docs not impofe upon an accurate obferver. The appear- ance of a body which really burns is very different from when a vapor of a confiderable diameter, as of a foot or eighteen inches, is kindled, and the combuftion is maintained only by the air contiguous to it, as when the vapor ifuing at the upper mouth of a furnace for melting iron ore is kindled by contact of any ig- nited body, the flame will then be found to have a thicknefs only of an inch or two, while the vapor near the center, furrounded by this flame, is mot inflamed, as appears from paper or other eafily combuftible matter being held in it without being kindled. Smoke confifts of palpable particles, elevated by means of the rarefying heat, or by the force of the afcending current of air, from bodies expofed to heat. ‘Thefe particles vary much in their properties according to the {fubftances from which they were pro- duced. Vapors alfo rifing from heated bodies, when condenfed by the coldnefs of air or other contiguous bodies, become palpa- ble, and therefore have the appearance, and may be confidered as fmoke. The fmoke arifing from combuttible' bodies confifts of parts, fome of which are generally combuttible, bet fo difficultly combuitible, that a greater heat is required than they poffefs while they are {moke, to effect their combuition. The flame alfo of combuftible bodies may be fo cooled by the application of cold air, or other cold fubftances, as that the combuition of the particles compofing it fhall be checked, and thefe particles thall become fmoke. Thus the flame of a candle is, by the coldnefs of the air, diminifhed more and more as it rifes higher, till at laft it is extinguifhed, before all its inflammable parts are con- fumed, and accordingly its point terminates in fmoke. The {moke of burning inflammable fubftances, when colleéted, is called foot. The fmoke of uninflammable fubftances, or of in- flammable fubftances not expofed to air, and confequently not burning, confiits of the f{ubitances not altered or decompofed, but only divided, as the flowers of fulphur raifed by heat in clofe veflels, and the flowers of fal ammoniac ; or it confifts of parts of thefe fubftances decompofed merely by heat, and not by com- buftion ; as the flowers of fulphur and of arfenic, from the mi- neral containing thefe called pyrites, expofed to heat in clofe veflels ; and the flowers of benzoin, fublimed by heat from the refin of that name. Cc gs that I ————————————————————— AE - ~ - - . or — ge a 4 — and - — # Sash —a - EA Sn . , TT cp pie pn i ee eA AS FL AME that of a body which is only made red-hot, by being pene- trated with a fire proceeding from fome other fubitance, which does not itfelf burn. Let a bar of iron be compared with a flint, when both are taken out of a fire fo intenfe as to give to cach of them a white heat, and the furface of the metal will feem covered over with a fmall flame, which is indeed very low, but bright and fparkling ; while nothing fimilar will appear on the furface of the flint. Befides, the flint will lofe its vivid color much fooner than the iron. If we obferve lead while it is fcorified in a cupel under a muffle, we fhall fee in a ftriking manner that the metal {hall be much more ardent and luminous than the cupel, although thefe two bodies are expofed precifely to the fame degree of heat; but this difference can certainly proceed only from the {mall flame which neceflarily accompanies the combuftion of the metal ; while the cupel which contains no combuftible principle, and which confequently cannot burn, does not exhibit any {uch appearance. | All bodies, therefore, which do really burn, feem to burn with ‘flame ; but the flames proceeding from the different combuftible bodies, differ very much from each other, ac- cording to the nature of thefe bodies, and to the particular fate of their phlogifton. I do not know whether the flame of any combuftible body be entirely pure. Such a flame would be nothing elfe than phlogifton feparated from all other fubftances reduced into vapor, and actually ignited. The flames of re@ified fpirit of wine and of perfect coal feem to be the pureft of all, becaufe they are accompanied with no fmoke nor fuliginous matter. Neverthelefs, the flame of fpirit of wine is accompanied with much water. See SPIRIT of Wine. All other flames are evidently mixed with hete- rogeneous fubftances, which difcover themfelves by dif- ferent qualities. The leaft pure of all flames is that of oils and of all oily matters, becaufe it proceeds from very compound bodies. This flame is always mixed not only with all the volatile principles of the oil, or oily body, but alfo with a confidera~ ble quantity of the fixed principles which are raifed by the deflagration, Befides, although it is confiderably luminous, all the phlogifton which it contains js not burnt : a portion of it remains combined in the ftate of coal with earth. Hence the flame of all oils is accompanied with a fuliginous fmoke, which blackens bodies that it touches. As this pro- perty belongs to the flames of all oils and oily matters, and to none elfe, it is a mark by which we may difcover whe- . ther FLOWERS ther the phlogifton of any body be in an oily ftate. See Oir, FULICINOSITY, SMOKE, and Soot. : The fame of metals is alfo accompanied with a fenfible {fmoke, which is even very confiderable and thick in cer- tain metals. But this flame does not, like that of oils, blacken fubftances which it touches; becaufe metals are not in an oily ftate. See METALS. Laftly, the flame of fulphur would be very pure, if it was not for the vitriolic acid, a large quantity of which is mixed with it. Perhaps the flame of this compound would be very pure, if the fulphur was previoufly mixt with fixed alkali to abforb the acid, in Stahl’s manner, and if it was made to burn fo weakly as not to be capable of kindling combuftible bodies. Sez SULPHUR. FLINTS. 8cEartHs (VITRIFIABLE). (¢) FLOWERS. By this name is generally underftood bodies reduced into very fine parts, either fpontaneoully, or by fome operation of art; but it is applied chiefly to volatile folid fubftances, reduced into very fine parts, or into a kind of meal by fublimation. Some flowers are nothing elfe than the bodies themfelves, which are fublimed entife, without fuffering any alteration or decompofition : and other flowers are fome of the con- (¢) FLinTs are femi-tranfparent or opake ftones, generally of 2 roundifh form, and covered with a white cruft, of a {mooth, uniform, fhining texture, {o hard as to ftrike fire with fteel ; cal- cinable by fire, fo as to become white, brittle, and, according to Henckel, heavier than before calcination ; not foluble by acids ; and vitrifiable only by the very violent heat of the largeit {fpecu- lums, fuch as that of Vilette, and not even by the focus of a lens of Tichirnhaus, according to an experiment of Neuman. They are found generally in beds of chalk and of fand, but never form- ing entire ftrata of rock, as jafper does. By long expofure to air and to the fun, they feem to decay, to lofe their luftre, their firmnefs of texture, and to be changed to a white calcareous earth or chalk. Hence they are almoft always found covered with a white'chalky cruft. They are alfo convertible into calca- reous earth’ by fufion, or vitrification with fo much fixed alkali, that they fhall refolve into a liquid mafs called the liqguamen of flints, and by precipitation from the fixed alkali by means of acids. See Liquor of FLINT. Flints are of the clafs of earths called witrifiable, becaufe thefe earths are generally employed, together with fixed alkali, as ma- terials in the making of glafs. Jee Grass, and BartHs (VI- TRIFIABLE). ftituent EL OW ERS ftuent parts of the body fubjected to fublimation, as wé {hall fee in the following articles, when we define the prin- cipal matters diftinguifhed by thc name of flowefs. FLOWERS ANTIMONY. Antimony, which is a mineral compofed of the femi-metal. called regulus of antimony and fulphur, is entirely volatile, ahd capable of being fublimed into flowers. To make flowers of antimony, an earthen pot or large crucible, in the upper and lateral part of which is an open-= ing, is placed in a furnace, and three or four aludels are fitted to it. The pot is to be made red-hot, and powdered antimony is to be thrown into it through the lateral open- ing, and the fublimation is then to be made. Thefe pro- jections of antimony are to be repeated till the operator judges ‘that the inner furface of the aludels is fufficiently covered with flowers, which are to be detached from thence with a feather. , $40 The veflels employed for this fublimation muft not be exaltly clofed, for two reafons; firft, that accefs of air favours and accelerates. all fublimations, and particularly this. Lemery obferves juftly, that the operation is accele- rated greatly by directing a blaft of wind upon the furface of the antimony. In the fecond place, if the veflels were perfeétly clofed, they would burft by the expanfion of the vapors, or of the contained air. Although all flowers of antimony be compofed of regulus of antimony and of fulphur, as the antimony itfelf is, they neverthelefs differ from -it effentially in many refpects. "They have not the fame metallic brilliancy. Their color is different fhades of white, grey, and yellow. They are powerfully emetic, Thefe differences prove, that anti- mony fuftains a confidérable alteration by this fublimation. This alteration confifts in the diminifhing the connexion betwixt the fulphur and the regulus of antimony. The difference of colors in flowers of antimony proceeds from the variable action of the fire and of the air upon this mineral during the operation. Probably the emetic quality of flowers of different colors alfo differs. But this dif- ference has not been obferved, as the flowers of antimony have not been much employed, becaufe of their uncer- tainty. RED FLOWERS of ANTIMONY. Lemery gives a procefs for making the red flowers of antimony. It confifts in diftilling eight ounces of antimony, mixed with fourteen ounces of fal ammeniac, or of flowers of fal am- moniac. FLOWERS thoniac. Some volatile alkali is raifed from the fal amro= niac, and red flowers are fublimed. The portion of volatile alkali which rifes in this opera~ tion is difengaged by the reguline part of antimony ; and as one part of this volatile alkali ats at once upon the {ul- phur and upon the regulus of antimony, an antimoniated volatile liver of fulphur is formed. = Thefe red flowers are a kind of kermes, and differ from the ordinary kermes in having a volatile inftead of a fixed alkali. They are emetic, purgative, diaphoretic, incifive, &c. as kermes is, and may be given in the fame dofe as kermes is ; but are feldom ufed. However, a kermes made with volatile alkali may have peculiar virtues, and deferves the attention of phyfi- cians; but in this cafe it ought to be prepared in a more certain manner, by employing uncombined volatile alkali. FLOWERS (ARGENTINE) of REGULUS of ANTIMONY. To make thefe flowers, regulus of antimony is put into an unvarnifhed earthen pot, which is to be placed in a furnace fo that its bottom may be red-hot, while its upper part fhall be much colder. The pot is to be covered with a lid, without luting it, and heat is to be applied during an hour or more. When the pot is cold, its internal furface, and alfo the remaining part of the regulus, is found covered with white flowers, in form of beautiful, tranfparent, and fhining needles. Thefc flowers are to be gathered with a feather. After this, a fecond fublimation may be commenced, and managed as the former was; and thus the whole regulus may be changed into flowers, which requires much time. Lemery direéts that a {mall lid or diaphragm fhall be placed within the pot, at the height of three or four fingers thicknefs above the regulus. But this appears to be un- neceffary. Mr. Beaumé docs not ufe this fecond lid. He only inclines the pot fo, that all the upper part of it fhall be out of the furnace. He makes the bottom of it very hot; and thus obtains a large quantity of flowers: ‘T'hefe flowers appear to be nothing elfe than the earth of regulus of antimony deprived of almoft all its phlogifton. They are not emetic nor purgative. They are not very volatile, and cannot eafily be reduced into regulus. They are foluble in aqua regia. All thefe properties, together with their remaining degree of volatility, fhew that they contain fome inflammable principle. They have alfo con- fiderable marks of a faline fubftance. ‘They have not only the appearance of a cryftallized falt, but are alfo entirely - foluble P——————————————————tt LS a— = ri SR RRC BRS r L OWERS foluble in water, as Mr. Beaumé obferves; although a large quantity of water, which muft alfo be boiling, is required for that purpofe. Eight ounces of boiling water are capable of diffolving half a grain of thefe flowers. From this property we may fufpe&t that regulus of antimony con- tains a {aline matter as one of its conftituent parts, which is conformable to the opinion of fome chemifts concerning {alts and metals. : Neverthelefs, if we confider that regulus of antimony cannot be deprived of all the fulphur with which it is united in its mineral ftate, we may {fuppofe that part of the acid of fulphur may, by uniting with the earth of the regulus of antimony, give the {aline qualities to the flowers of this metallic fubftance. : FLOWERS of ARSENIC. The white flowers of arfenic are nothing but white arfenic itfelf which being a volatile fubftance, unalterable by fublimation, may be raifed altogether, without id change. Flowers of arfenic are made, as all other flowers are, by fubliming arfenic. See SUBLIMATION. We ought to obferve that they are not perfectly white, unlefs the arfenic from which they have been fublimed has been perfectly dephlogifticated and white. 1f the arfenic which is fublimed be mixed with a little fulphur, the flowers will be more or lefs yellow, or red, according to the quantity of fulphur which is {fublimed along with them. If the arfenic be ina reguline ftate, ‘or confiderably phlo- ‘Ricated, its fowers will be more or lefs greyifh or brown. i we fee veins of thefe different colors among the arfenic which is found in commerce, and which 1s ob- tained by fublimation in great WOrKs from arfenical mi- nerals. As arfenic is very fufible, when thefe flowers fix them- felves to any fubftance confiderably heated, they fuffer a kind of fufion, are agglutinated thysther 2h form the denfe, compaét, heavy, thining malics which are in the fhops of druggifts, ‘The nature and properties of flowers of arfenic do not differ from thofe of arfenic. See ARSENIC. FLOWERS of BENJAMIN, or BENZOIN. To make flowers of benjamin, let 2 quantity of benjamin be put into 2 varnifhed earthen pan, which is to be covered with another inverted pan of fone ware. The edges of thefe two pans ought to have been ground upon a ftone, fo that they fit well to each other. They are to be luted to- ‘gether with paper dipped in pafte. {*he earthen pan con- taining ELOWERS taining the benjamin is to. be put upon a gentle fire, and which is not capable of raifing the oil of the benjamin. With that heat the {fublimation is to be performed : when the veflels are cooled, they are to be unluted, and great care is to be taken that they be not thook. If the fublima- tion has been performed, the inner furface of the upper earthen pan will be found covered with fine fparkling flowers like a very pure falf, forming cryftals like flattened needles. A confiderable quantity alfo of thefe flowers is generally found which are not raifed, and which cover the furface of the remaining benjamin. ‘The flowers are to be fwept off with a feather. The fuccefs of this operation depends on the degree of heat given, and the time employed. If the heat be too great, a part of the oil of benjamin will rife together with the flowers, which will thence receive a dirty yellow tinge. In this cafe they muft be again {fublimed, and with 2 lefs heat. If, on the contrary, 2 fufficient degree of heat is not given, or the operation has not been long enough con- tinued, all the flowers which the benjamin is capable of furnifhing will not be procured. The fame benjamin will, by repeating the eperation, furnifh more flowers. The procefs formerly ufed to make thefe flowers confifts in putting the benjamin in an earthen pot, to the mouth of which is fitted a paper, or pafteboard conical head. But the method defcribed above, which is propofed by Mr. Beaumé, feems to be preferable : becaufe the paper or pafteboard heads abforb many flowers, which are confe- quently loft, and alfo becaufe the earthen veflel employed by Mr. Beaumé has a greater furface than. the pot ufed in the ancient method; and quantity of furface is always favourable to fublimation. The flowers of benjamin are a true concrete, volatile, and oily effential falt of benjamin. They have the {mell of benjamin, and are inflammable, from the effential oil which enters their compofition. They are {foluble in water and in fpirit of wine, which fufficiently proves their faline nature. Accordingly, Mr. Geoffroy obferves, that this {alt oad be obtained by treating benjamin with water, and by cryftallization. Benjamin is probably not the only refin from which an effential falt of this kind may be obtained : perhaps, even oll refins contain fuch effential falt, in. greater or lefs quantity ; and this is certainly one of thofe which contain a great quantity of it. Flowers FLOWERS Flowers of benjamin are confidered in medicine as if= cifive, dividing, and favoring expectoration, and are there~ fore given in the vifcous afthma. They may be given from fix grains to twelve. See RESINS, and SUBLIMA- TO LOWERS of SAL AMMONIAC, The flowers moniac are nothin elfe than fal ammoniac fub- yh : "for this ain falt fuffers no decompofition by fublimatjon, The procefs for making thefe flowers contains nothing fingular, excepting that an equal part x decrepitated common falt is generally mixed with the fa ammoniac, in order to divide this latter falt, and to facili= tate its fublimation. By this fublimation, fal Bpas may be purified from fuliginous and other matters, wih which it is generally mixed.’ But it may be Be more conveniently purified by folution in water, by filtra- tion, and by cryftallization. For this falt has the Jros perty of raifing along with 1t in fublimation very fad matters, as we fee from the example of the flowers S a ammoniac tinged with copper and with iron, galls i martis, and ens weneris, which are nothing elfe than fa ammoniac fublimed with iron and with copper. See Am- HAS WER of SULPHUR. Flowers of fulphur are crude fulphur fublimed in an apparatus of Rusty, Sulphur cannot be decompofed without an tops Joss fubftance in clofe veflels. Therefore flowers of i phur have no properties different from thofe of pure fulphur in UR. i Me ZINC. Flowers of zinc are the metallic earth of zinc, deprived of almoft all its. phlo- gifton, and raifed in light flocks from deflagrating Bt, To make thefe flowers, zinc 18 to be put into 2 Wi open crucible, fet in a furnace which draws air hy . When a white heat is raifed, the zinc kindles and spt with a white, vivid, dazzling flame, Agchmpinied wit a confiderable quantity of white fmoke. This fmoke cons denfed in white light flocks, which float all Foun: 59 laboratory. The greateft part of ‘thefe flocks, however, themfelves to the fides of the crucible and to i] ik They are called flowers of ZINC nihil album, or pomp 0 i Although thele flowers are raifed into {moke in this operation, like a very volatile fubftance, they wi Hay very fixed, as metallic earths are, when well dephlogiiti= : ; Prod Rae cated ; and are fo incapable of being again fublimed, oe FLOW ERS they refift the moft violent fire, and are fooner melted than fublimed. If they are then raifed in {moke during deflagration, this effect is produced by the activity with which the zinc burn§; and for the fame reafon, earths and coals extremely fixed are found in foot of wood and of moft other combuftible matters. The flowers of zinc are foluble in acids, nearly as zinc is. See Zinc. The caufe of this may be, that they retain fome phlogifton. « But they are difficultly reducible into zinc, and were even believed to be incapable of reduc- tion, till Mr. Margraaf publithed a method of reviving them, by expofing them to a ftrong heat together with fome inflammable fubftance in clofe vefiels. In the crucible ufed for the preparation of flowers of zinc, a confiderable quantity of thefe flowers is found fixed to its fides, and to the furface of the zinc, if any remains unburnt. Thefe latter flowers are much lefs white and light than the former. ‘They have been produced by the part of the zinc which burnt lefs vehemently than the reft, Their color is greyifh, from a certain quantity of phlo- gifton which they retain. Flowers of zinc alfo are obtained from furnaces in which minerals containing zinc are fmelted, particularly that of Rammelfberg. They adhere in great quantitics to the upper part of the internal furface of the walls of the fur- naces. But as thefe flowers fuftain a great heat, they are half fufed and agglutinated together, forming mafies, which muft be taken eff frequently in order to clear the furnaces, Flowers of zinc in this ftate are called cadmia arnacum, or pompholix. See CapMIA and ZINC. FLOWERS of VEGETABLES. slumiry. (f) Frowers. In this article, which is extrated from Dr. Lewis’s notes on Neuman’s Chemiftry, the colors only of flowers fhall be confidered. Very few of the colors of flowers of vege- tables are durable, or can be made durable by any means known. ‘The only permanent color is yellow. I'he red, the blue, the purple, the crimfon, and the wiskt, are very perithable. Many flowers lofe thefe colors merely by being dried, efpecially by being {lowly dried in a thady and not warm place. The: colors of all of them perith by keeping, even in the clofeft vefiels. The more haftily they are dried, and the more perfeftly they are fecured from air, the longer they retain their beauty, The color- ing matter of flowers extracted and applied on other bodies is full more perifhable, BLUE om op — ra —— - PE Re ee ait pa mal FLELDITY FLUIDITY. Fludity is the ftate of a body whofe integrant parts are fo difunited and incoherent, that no fenfible refiftance' is oppofed to their feparation in any direction ; but which are neverthelefs fufficiently at- tralted by each other, to remain adjacent, and to form an gregate body. gale hs 0 feidity is a middle ftate betwixt hardnefs, in which the integrant parts of bodies adhere together firmly, and the entire want of aggregation, in which the Integuant : parts Brug Frowers. The color of many blue flowers is extrafted by infufion in water; but from others, water acquires only a urplith hue. Of thofe which have been tried, not one gives a De color to {pirit of wine: fome give no color, and fome give a reddifh color. ‘The exprefled juice of thefe flowers is generally blue. The blue juices and infufions are rendered red by all acids : and the molt florid red is given to them by marine acid. The flowers alfo, by maceration, impart a red- color to acid liquors. Alkalis fixed and volatile, and lime’ water, change thefe blue colors to green. And thofe infufions or juices which have nothing of the color of the flower, fuffer the fame - changes from the addition of acid and alkaline liquors. Even when the flowers have been kept till their colors are loft, their infufions acquire a red color from acids, and a green color from alkalis, but in a lefs degree than when the flowers were frefh, The red coler produced by acids is fcarcely more durable than the original blue: applied upon other bodies, and expofed to air, it gradually degenerates into a faint purple, and at lait difappears, . i aving a ftain behind. ‘The green produced by alkalis ous Jo a 2 low, which does not fade fo foon. The green made by lime-water is more permanent and beautiful. Green lakes, prepared from blue flowers by means of lime-water, have been ufed by painters. The flowers of ¢yanus have been much commended for affording elegant and blue pigments. But Dr. Lewis has not been able to extra& from them any blue color, They retain their color, when haftily dried, longer than other blue flowers, but do not communicate their original color to ruum, ; yo fs a readily communicate their color to water ; and thofe of a full red color give to a reltified fpirit alfo a deep red tin®ure, brighter, though fomewhat paler, than the Wales is. fufion. But the lighter red flowers, and thofe which are purp i h impart little color to pure fpirit, ‘The colors of infufions of thefe flowers are fuppofed to be heightened by acids, and to be Fo, ‘dered green by alkalis. But this is not univerfal. For amongt thofe examined by Dr. Lewis, the rofe colors and purplifh ic were changed by acids nearly as blue” flowers are; but the fu FLU KD IT ¥ parts of bodies are fo feparated and removed from each other, that their mutudl attraction‘fs no longer fenfible, A body may be fluid in’ two manners; firft, by the figure of its primitive integrant parts, fo that each of thefe’ parts fhall not touch any other but in one point, or in one infinitely fmall fide, and confequently have but little or no adhefion. Such a body muft neceflarily and naturally be fluid. Fire feems to be the only body poffefied of this eflen- tial fluidity. ! RE "The! fecond “manner by which a body may be rendered fluid is; ‘to leflen: the. conta&t ‘of the integrant parts, to disjoin them); ier even to feparate them from edch other by deep reds. -wére> not. The deep ‘infufion of ‘red poppies was tarned by alkalis not to a green, but'to a dufky purple. Yervow ; FLowERs communicate: to water and. to {pirit of wine durable yellow colors, not alterable but in degree by acids or by alkalis; the former only rendering them ‘paler; and the latter, as ‘allo: alum, rendering them deeper. Wool, or filk, impregnated with a folution of alum and of tartar, receives, on being ‘beiléd. with the watery infufion or decoftion, a durable. yellow dye, A durable yellow lake is prepared by precipitating with:alum an‘infufion of yellow flowers made in an alkaline ley. In fome of the orange: colored flowers the yellow matter feems to be of the fime'kind as that of ‘the pure yellow flowers’; but the red matter feemstto'be different from ‘that of the pire red flowers. "The yellow matter is extrated from thefe flowers by water ; and the remaining réd matter is extradted by {pirit of wine, or by a weak. {olution of fixed alkali in water. Such are the {affron - colored flowers of, Carthamus. Thefe flowers, after the yellow matter has been extracted by water, are faid to give a red tinc- ture to ley, from which a deep red fecula fubfides, called Safflower, Spanijh red, and China-lake. This pigment gives a beaunful red color to fpiritof wine, but none to water. ‘I he yellow farina or fine duft, refting on the tips of the Jtamina of flowers, gives a fine bright yellow color to fpirit of wine, and a duller yellow color .to water. The colors of both the watery and fpirituous tinftures were heightened by alkalis, rendered red by acids, and again reftored to a yellow by adding an alkali. = This is the only known inftange of the yellow color of a vegetable being rendered red by acids. Waite Frowers, or their exprefled juices, impart a green color to alkaline leys, but have not been obferved by Dr. Lewis to give a red color to acids.. The white flowers cf the common wild convelvulus give a deep yellow or orange color to water, which is affected by acids, by alkalis, and by alum, as the in- fufions of yellow flowers are. “The white flowers of Xeranthe mun givea beautiful yellow color to water acidulated with {piritof nitre. Vou. 1, Dd the o fa : 3 : ee in bt vio. irre ere —— SE EAR A SS — I . = —————" - we ~ —————— E p Te — i er a a Ae HT a * “ a a - : : 4 3 Hr Etna leon ’ oo alah ERE 5 : SER ha gh bi Si IR: ae FLUKD IT YI the interpofition of a fluid. All bodies which can uly be: fluid in this manner, are evidently not eflentially fluid. On the contrary, they are naturally more or lefs hard and folid, and can only have a mediate or fecendary fluidity. Such all bodies in nature appear to be, excepting fire. Hence, without fire no fluid would exift ; all bodies would cohere together, and form a fingle, folid mafs ; and hence fire is the principle of all fluidity. But when a body is rendered fluid by fire, it may then be capable of giving fluidity to other bodies. Water, for inftanee, the fluidity of which is certainly caufed by fire, may, by interpofing itfelf betwixt the integrant parts of gums and falts, give to them 2a fluidity fimilar in fome refpects to its own. We muft not confound the fluidity received directly from fire with the fluidity received from bodies rendered fluid by fire. Some fubftances are incapable of receiving fluidity dire@tly from fire, but only through the intervention of fome other fubftance previoufly rendered fluid by fire. Such are gums, which are rather decompofed than rendered fluid by fire, but which are readily foluble in water, Other bodies may be either rendered fluid direitly by fire, or fecondarily through the intervention of another "body pre- vioufly rendered fluid by fire. Such, for inftance, are falts. They become fluid when expofed alone to the action of fire, and are alfo capable of liquefaction by water. The principal difference betwixt a body rendered fluid merely by the action of fire, and another body rendered fluid by the interpofition of a fluid fubftanee, is, that the integrant parts of the latter body adhere to thofe of the interpofed fubftance ; and that this adhefion or affinity is the caufe of the fluidity of that body. ; This fecondary fluidity, therefore, given by interpofi- tion of a fluid fubftance, is nothing elfe than a folution. "The fuidity given immediately by fire is called by chemifts, Gon ; we therefore fay that a falt is diffolved in water, but not fuf-d or melted. “This latter expreffion is frequently ufed, though very improperly. ! Thele es i et differences betwixt the fluidity of fire, which is effentially fluid, the fluidity of bodies fufed merely by the action of fire, and the fluidity of hodics rendered fluid by the interpofition of others alread fufed, require that thefe different kinds of fluidity fhould be diftinguithed by names appropriated to each. At prefent no fuch precife expreffions have been ufed to denote them. Bodics habitually fufed might be called guid, and shots Ww rr vor which have only a fecondary fluidity might be called %guid. But what nam= fhall be given to he primary and effential fluidity of fire? This want of fuitable expreflions thews the little atten- tion given by chemifts and natura] philofophers to fluidity, and to the properties of bodies by which they give and receive fluidity. From not having refleted on the pro- perties of fire, and upon the effects which it produces upon other bodies; we have confidered thofe fubftances as having an’ independent fluidity, which we have generally feen in 2 fluid or fufed ftate; fuch as air, ethereal fpisits. mercury, fpirit of wine, and even water and oils ; although we fre- quently fee thefe two laft mentioned fubftances become folid. by cold, or want of adive fire. - The fixation of mercury by a fufficient degree of cold, the poflibility of which is. fufpected in the AA of the Theary of Chemifiry, and is afcertained by experiments of foe Members of the Aca- demy at Peterfburgh, induces us to conjecture, that every body is naturally folid or hard; and that all fluid bodies receive their fluidity from fire, which is the only fubftance eflentially fluid. However that may be, this is evident, that as the aggre- gation of every body which is fluid or liquid muft be broken, or much diminithed, fluidity is the moft favourable ftate for the formation of new unions; and that every {ubftance which forms a new combination muft neceffarily have or acquire this ftate. Therefore a precife and extenfive know - ledge concerning fluidity, and the properties of bodies by which they give and receive fluidity, is exceedingly im- portant in chemiftry. Sez AGGREGATION, SOLUTION, Fire, Fusion, and L1QUEFACTION. FLUOR, This word, ufed as an adjective, is applicd to fignify the habitual fluidity of any fbftance, or that property by which a fubftance cannot be rendered folid, and is employed as an epithet to diftinguith fuch fubftances from others of the fame kind, but which are habitually folid, or which may be rendered folid. Acids, for inftance, which are habitually fluid, as all the mineral and fome vegetable acids, are called fluor acids, in order to diftinguith them from the acid of tartar and acid effential {alts, which are naturally concrete. Alfo volatile alkali treated with quicklime, or with metallic earths, fo that it is always liquid and not cryftallized, is called fluor volatile altali, to diftinguifh it from the concrete and cryftallizable volatile aikali, Dda By v F LU QR wor, ufed fubftantively, is meant a certain kind of te fo, is fufible, or which facilitates fufion. Such are the greateft part of Jpars, which are called fluors. Thus, for example, in talking of a white or colored fpar, which is found in the matrix of an ore, we fay that this matrix is mixed with a white, green, or yellow fluor. See Spas. (zg) (g) Fruors. Fluors are ftones or {pars of different colors, purple, green, yellow, &c. more or lefs tranfparent, which are commonly found in veins of ores, and ferve as the matrix to the minerals which they invelop. Moft of them affeét a cubical form, but others are found in lumps which have no determinate fhape. They may be diftinguifhed from other ftones by the following erties. bi They are not fufficiently hard to firike fire with fteel. - By this property they are diftinguifhed from the colored quartz cryltals, called falfe emeralds, falfe rubies, &c. which ‘names have alfo been improperly applied to the cubical colored fluors. 2. They are not foluble by acids, and thus:are diftinguithable from calcareous fpars. {laa _ When calcined without addition, and ‘mixed with water, they do not form plafter ; and when calcined with addition of in- flammable matter, they cannot be formed into the Bolognian phofphorus. Hence they may be diftinguifhed from the gypleous phofphoric {pars and ftones, y of 4. They are fufible by fire without addition, according to M. Engeftrom, and M. D’Arcet. ot 5. They greatly facilitate the fufion of calcareous and argilla- ceous earths; and alfo of the topaz, according to Mr. Pott. Chey are much employed in the inciting of ores, as they promote the of the adhering earths. on hen expofed to fire till they become red-hot, they emit fome lucid rays in the dark ; but their light 1s very weak, and afterwards they crackle and break into {mall pieces: whereas, the gypfeous phofphoric pars expofed to the fame heat emit a, vivid light, and then break afynder into pieces not fo pulverable as thofe of the heated fluors, . , M. Margraaf has made experiments, in order to difcover the nature of thefe ftones. He afcertained the diftinttions above mentioned between them and the gypfeous fpars, and therefore infers that they are not compounded of vitriolic acid with calca- reous earth. He obferved fingular appearances on mixing them: with vitriolic and other acids, and fubjeing the mixtures to diftillation. Hi Eight ounces of the powder of a green fluor, being ize with an equal weight of pure oil of vitriol, and diftilled toget st with a gracuated heat, yielded after the watery part of the ac1 had palied, a fine white fublimate, which arofe and Wheed io FL 8X - FLUX. This word is fometimes ufed {ynonimoufly with fufion, For inftance, an ore, or other matter, is faid -to be in liquid flux, when itis completely fufed. But the neck of the retort, and even paffed into the receiver. The firft parts of this fublimate which arofe, appeared like butter of antimony ; and like this butter, they melted by the heat of a live coal, brought near the neck of the retort: But the parts which arofe towards the end of the operation, with the greateft - degree of heat, could not be melted by that heat. The retort being broken, a refiduum was found weighing 12 oz. Hence 4 oz. of oil of vitriol remained united with the {fpar. The bottom of the retort was obferved to be pierced with holes. Laftly, the liquor, which had pafled into the receiver, and the white {ubli- mate, had very fenfibly a fulphureous fmell. The fublimate, triturated a long time in a mortar with ‘hot diftilled water, dif- folved, and paffed through a filter. = To the filtrated liquor {ome fixed alkali being added, a precipitate was formed, which being well wathed and dried, was ready melted by fire into a mais refembling porcelain. The fame excellent and accurate chemiit produced the fame effets upon this ftone by fubftituting inftead of the vitriolic acid, the nitrous, marine, phofphoric, or the concentrated acetous acids, Further experiments on fluors have been made by Mr, Scheele, an account of which is given in the Swedith Tranfaétions for the year 1771; and from thence an abftraét in Englifh is publifhed in a pamphlet, called ‘¢ An eafy Method of Affaying and Clafling ¢¢ Mineral Subftances, by John Reinhold Forfter, I. R.S.” Mr. Scheele obferved upon diftilling a mixture of fluor with oil of vitriol, that the fumes which arofe corroded the glafs veflels, and formed a cruft upon the water contained in the receiver, which cruft gradually became thicker during the opera. tion. ‘I'he water alfo in the receiver was found, on examination, to contain a confiderable quantity of a zeaw acid, difengaged from the {par by the oil of vitriol. The cruft formed by the fumes acting upon the water of the receiver, was not foluble in acids, but was diffolved by oleum tartari per deliguium, with which it formed a gelatinous {ubftance. It was not fufible by fire without addition ; but when mixed with fixed alkali was vitriied, This vitrified fubftance being melted with a large portion of fixed alkali, deliquefced, and afforded a precipitate upon adding to it an acid. Mr. Scheele concludes from thefe experiments, that the cruit thus formed from the fumes uniting with water, is a true flinty fubffance, and that flints, therefore, confift of this new acid of fluors united with water. From other experiments he is led to conclude, that the earth, which is united with this new acid in the fluors, is of the calcareous kind: for upon lixiviating with water the mals that remained after the diftillation of fluor with oil of vitriol, and Dd; adding F'i ¥V'K But the word flux is generally ufed to fignify certain faline matters, which facilitate the fufion of ores, and other adding falt of tartar, a calcareous earth (he fays) was precipitated. Further, the acid of the fluor which had pafled over into the receiver and mixed with the water, being added’ to lime-water, a white powder was precipitated, which though not in the form of cryflals, was found to poflefs all the properties of the original fluor, This regenerated fluor being diftilled with oil of vitriol, formed the fame kind of craft on the furface of the water in the receiver. When alkohol, oil of olives, or oil of vitriol, were put into the receiver inftead of water, no cruft was formed. The fame kind of cruft was formed, when inftead of oil of vitriol, the nitrous or marine acids were diftilled with the fluor. ‘By thefe two laft mentioned acids the fluor could be diffolved. Upon adding to the folution a mild volatile or fixed alkali, a powder was precipitated ; and upon adding to the fame {olution fome vitriolic acid, a gypfecus powder was precipitated. : The calcareous bafis was likewife feparated by mixing with one part of the fluor four parts of fixed alkali, melting this reixture, and lixiviating the fufed mals in water; by which means the calcareous earth of the fluor was precipitated, and a {aline compound remained in the water, confifting of the acid of the fluor united with the fixed atkali. Mr. Scheele examined the acid of the fluor, which though not diftinguithable in {fmell from marine acid, differed materially in this refpe, that the former acid, united with a calcareous earth, forms a folid fubftance; while the latter is known to form with that earth a very deliquefcent falt. When the acid of fluor was diftilied with a gentle heat, the ftronger part of the acid, which did not come over till towards the end of the diftillation, formed 2 craft with the more watery partsthat had pafled firft, and alfo corroded the glafs veficls. Upon mixing the acid of fiuor with a fixed alkali, a gelatinous fubfiance was produced, from which; by adding lime-water, 2 regenerated fluor was precipitated. This 2¢id did alfo form gelatinous fubftances, when united with volatile alkali, magnefia, and carth of alum: But when fatu- rated with -lime water, a regenerated fluor was precipitated. “The powers of this acid on metallic fubftances were next examined, Gold was not affefted by the acid of fluor, either alone or mixed with foirit of nitre. Silver, guickfilver, and lead, were not acted upon. Copper was partly diffolved, fiom was afled upon vio- lently; and the fumes, which arofe during the folution, were inflammable. Tir was not afted upon; but its calx was diffolved: Bifmuth, cobalt, and regulus of antimony were not diffolved by this acid. Zinc was diffolved in the {fame manner as iron. his acid occafioned a precipitation in the folutions of filver and quickfilver in nitrous acid. Jt did not precipitate a folution of corrofive fub- limate, nor a {olution of lead in nitrous acid. - matters FL 7u0 xX: matters which are difficultly fufible in eflays and reduc- tions of ores. Fixed alkalis, nitre, borax, tartar, and common f{alt, are the faline matters of which fluxes are generally compofed. But the word flux is more particularly applied to mixtures of different proportions of only nitre and tartar; and thefe fluxes are called by particular names, according to the proportions of thefe ingredients, as we fhall fee in the following articles. FLUX (WHITE). White flux is made with equal parts of nitre and of tartar detonated together, by which they are alkalifed. The refiduum of this detonation is an alkali compofed of the alkalis of the nitre and of the tartar, both which are abfolutely of the fame nature. As the pro- portion of mitre in this mixture is more than is fufficient to confume entirely all the inflammable matter of the tartar, the alkali remaining after the detonation is perfectly white, and is therefore called white flux ; and as this alkali is made yoy quickly, it is alfo called extemporancous alkali. When 2 {mall quantity only of white flux is made, as a few ounces, for inftance, fome nitre always remains undecom- pofed, and a little of the inflammable principle of the tartar, which gives a red or even a black color to fome part of the flux: but this does not happen when a large quantity of white is made flux; becaufe then the heat is much greater. ‘This fmall quantity of undecompofed nitre and tartar which remains in white flux is not hurtful in moft of the metallic fufions in which this" flux is employed ; but if the flux be required perfe&tly pure, it might eafily be difengaged from thofe extraneous matters by 2 long and ftrong calcination, without fufion. See CALCINATION, FLUX (CRUDE). By crude flux is meant the mixture of nitre and tartar in any proportiops, without detonation. Thus the mixture of equal parts of the two falts ufed in the preparation of the white flux, or the mixture of one part of nitre and two parts of tartar for the reparation of the black flux, are each of them a crude flux Fefore detonation, It has alfo been called white flux, from its color ; but this might occafion it to be confounded with the white flux above defcribed, The name, therefore, of crude flux is more convenient. ' Crude flux is detonated and alkalifed during the reduc- tions and fufions in which it is employed, and is then changed into white or black flux, according to the propor tions of which it is compofed, This detonation produces good effets in thefe fufions Sn reduétions, if the aio d + anc HOR GE and extravafation of the detonating matters be guarded againft. Accordingly, crude flux may be employed fuc- cefsfully in many operations; as, for inftance, in the ordi- nary operation for procuring the regulus of antimony. LUX (BLACK or REDUCING). Black flux is produced from the mixture of two parts of tartar and one part of nitre detonated together. As the quantity of nitre which enters into the compofition of this flux is not fuffi- cient to confume all the inflammable matter of the tartar, the alkali which remains after the detonation contains much black matter, of the nature of coil, and is therefore called black flux, . This flux is defignedly fo prepared, that it {hall contain a certain quantity of inflammable matter; for it is thereby capable not only of facilitating the fufion of metallic earths like the white flux, but alfo of reviving thefe metals by its phlogifton. From this property it is alfo called reducing flux ; the black flux, therefore, or crude flux made with fuch proportions of the ingredients as to be convertible into black flux, ought always to be ufed when metallic matters are at once to be fufed and reduced, or even when deftruc- tible metals are to be fufed, as thefe require a continual fupply of phlogifton to prevent their calcination. See NiTre, ReEpucTioN, and TARTAR, FORGE. An ordinary forge is nothing but a pair of bellows, the nozzle of which is directed upon a {mooth area, on which coals are placed. The nozzle of a pair of bellows may be alfo directed to the bottom of any furnace, to excite the combuition of the coals placed there, by which a kind of forge is formed. In laboratories, there is generally a {mall furnace confifting of one cylindrical piece, open at top, which has at its lower fide a hole for receiving the nozzle of a double bellows. This kind of forge-furnace is very convenient for fufions, as the operation is quickly performed, and with few coals. In its lower part, two inches above the hole for receiving the nozzle of the bellows, may be placed an iron plate of the fame diameter, fupported upon two horizontal bars, and pierced near its circumference with four holes diametrically oppofite to each other. By this difpofition, the wind of the bellows, puthed forcibly under this plate, enters at thefe four holes; and “thus the heat of the fire is equally diftributed, and the crucible in the furnace is equally furrounded by it. This contrivance is ufed in the forge-furnaces for melting copper, F~R: U1 TT 8 copper; with this difference only, that thefe furnaces are iquare, which is a matter of no confequence. As the wind of bellows ftrongly and rapidly excites the action of the fire, a forge. is very convenient when a great heat is to be applied quickly: but it is not fuitable when the heat is to be gradually encreafed. The forge or blaft of bellows, is ufed in feveral opera- tions in. {mall; as to fufe falts, metals, ores, &c. Itis alfo much ufed in works in the great, which require ftrong heat, without much management, and chiefly in the {melting of ores, and fufion of metallic matters. FRITT. Frittis a mixture of feveral fubftances in- tended to be fufed together for the purpofe of making glafs. After thefe fubftances have been mixed together, they are generally expofed during a certain time to a more or lefs ftrong heat, which is, however, incapable of compleatly fufing them. ‘The intention of this operation is either to effet a flight union betwixt thefe matters, or to free them more perfectly from any inflammable or extraneous matter, by this calcination. See VITRIFICATION. FRUITS. (5) FULIGI- (bh) Fruits are confidered only as coloring materials in this article, the greateft part of which is extrated from a note of- Dr. Lewis to his Tranflation of Neuman. The red juices of fruits, as of currants, mulberries, elder berries, morello and lack cherries, when infpiffated and dried, may be again diffolved in water, to which they give nearly the fame red color as they do when frefh. Rectified {pirit extralts the tinging particles, and acquires a brighter color than the watery folution : becaufe much of the mucilage is left undifiolved by the former. The red folutions and the juices are fometimes made dull, and fome- times more florid, by acids, and are generally rendered purplith by alkalis. The colors of thefe juices are generally perifhable. They are not deftruétible by the fermentation of the liquors ; but they quickly decay when the juice is fpread thinly on any fub- ftance, and dried 1n open air. The bright lively reds are {foonett changed. The dark, dull red ftain of the black cherry is con- fiderably durable. ‘The bright red fruit of the gpuntia or prickly pear 1s an exception to the above rule; as it gives, according to Labat, a beautiful red dye. The ripe berries of buckthorn {tain paper of a green color. ¢ From thefe is prepared the fubitance called Jap-green, whichis a pigment fufficiently durable, fbluble in water, but not mifcible with oil. The fame berries dried whilft green, and macerated in alum-water, are {aid to yield a yellow pigment ; and when they have grown over-ripe, a purple } piament. FURNACE FULIGINOSITY. By this word is meant foot, or the black matter which accompanies the flame of oils and of oily fubftances. See Soor. FULMINATION. Fulmination is the fudden and violent explofion and inflammation of certain bodies, which are therefore called fulminating. Such are the explofions of fulminating powder and of fulminating gold. The explo- fion of thefe matters is called fulmination, from the noife accompanying it, by which it refembles thunder. FU RNAC E. Furnaces are chemical inftruments ufed for containing combuftible matters, by the burning of which the heat requifite for operations is procured ; and alfo for containing the fubftances themfelves to which the heat ought to be applied. As chemifts require for different operations all the poflible degrees of heat, from the weakeft to the ftrongeft, and as the form of the furnaces contributes greatly, as we fhall fee, to produce the different degrees of heat; they have contrived many furnaces of different forms and con- ftrudions ; but all thefe furnaces may be reduced to a fmall number of general difpofitions, which we fhall now defcribe. The fimple furnace is a kind of hollow tower, cylindrical or prifmatical, with two doors or principal openings ; the one below, called the door of the afb-hole ; and the other immediately above this, called the door of the fireplace. Be- twixt thefe two doors a grate is placed horizontally acrofs the interior part of the Breer, dividing the whole cavity of the furnace into two parts ; the lower part is called the a/b-hole, becaufe it receives the athes which fall from the pigment. Woollen cloth, prepared with alum and tartar, re- ceives, on being boiled with the berries, a perifhable yellow dye. The French berries, or graine d’ Avignon, one of the moft perifh- able yellow dyes, is a berry of the fpecies of buckthgrn, tis faid that the berry of the beliotropium tricoccum Rains paper of a green color ; and that this green is {oon changed toa blue; that the com mon blue paper receives its color from this juice ; and that the red rags called rurnfol, employed for coloring wines and other liquors, are tinfured by the fame juice turned red by acids. Mr. Niflole fays, that the coloring juice is obtained, not from the berries, but from the tops of the plant. The Dutch are faid to prepire thefe rags from other materials, of which archil is a principal one. I'he feeds of fome plants, as of peony, are covered with a fine fhining red membrane. The pellicles of the feeds of an Ameri- can tree afford the red mafles called anaotto, oplean, and roucoy. See ANNOTTO. bet Lat fires FURNACE fite-place. The door of the afh-hole gives admittance to the air neceffary for maintaining the fire within the furnace. The upper cavity of the furnace is called the fire-place, becaufe it contains the combuftible matters. Through the door of the fire-place freth fuel is to be introduced, to fupply the place of what is confumed. The fimple furnace, fimilar to that ufed in kitchens, is fufficierit for many chemical operations. In the fire-place, amidft the coals, crucibles may be placed for the fufion of fufible matters ; fuch as lead, tin, bifmuth, &c. or for the calcination of matters which require but little heat for their calcination ; fuch as the alkali for making Pruffian blue, bezoar mineral, &c. : On this furnace may alfo be placed bafons for evapora- tions, alembics for diftilling in the water-bath, pots filled with fand for digeftions and diftillations to be performed by means of a fand-bath and a geatle heat, either with alembics or with retorts. As feveral of the operations made with this furnace are of long duration, and as the furnace requires a continual fupply of fuel ; chemifts have contrived to adapt to ita magazine of coals in form of a hollow tower, clofed in its upper part, and fo difpofed, that while the coal of the fire-place is confumed, that of the tower falls down and fupplies its place. The furnace thus difpofed is called an athanor, or the furnace of fluggards. See ATHANOR. See Prate IL fig. 2. ‘ The lamp-furnace is a kind of athanor, in which the heat is produced and maintained by the flame of a lamp intro- duced within it. This furnace has evidently no occafion for an ath-hole, a grate, or a fire-plage. It has only one opening below, through which the lamp is introduced, and a kind of fmall chimney made in its upper and lateral part, for circulation of air, to keep up the flame of the lamp, and to give vent to the fmoke. This furnace is very con= venient for diftillations which require little heat. A water- bath or fand-bath may be fitted to it. It is particularly ufeful for digeftions. * The reverberatory furnace is the fimple furnace, the fire- place of which is covered with a piece of the fame diameter and form as the furnace, which is generally cylindrical, This piece is crofled in its lower part by two bars of iron placed horizontally and parallel to each other, and at its upper edge it has a femi-circular cut. This piece confe- quently forms a third cavity, which is called the Laboratory, nr becaufe ro aE pn Ta lr ——— EE — IR ni sa — - - Rn a a IIRL Je SRY ami FURNACE becaufe it is intended to receive the retorts containing the matter to be diftilled. The femi-circular cut.is made to give paflfage to the neck of the retort, which, as we have faid under the article DisTILLATION, ought to be inclined at an angle of 45 degrees. The ufe of the two bars at the bottom of the laboratory is to fupport the veffel placed these. 1d io be Above the piece we have now defcribed is a fourth piece placed, the form of which is that of a fpherical cap, or of an inverted dome: it is accordingly called the dome. This dome has an equal diameter to the other piece to which it js to be fitted; and in its lower edge it has a femi-circular cut, which correfponds with the fimilar cut of the lower piece; and thefe together form a circular opening: the dome has in its top another opening or fhort tube, through which the air.contained in the furnace paffes, and is a kind of chimney. The ufe of the dome is to keep up the heat all around the retort which is placed in the furnace, and to apply a certain degree of heat to the upper part or vault of the retort, by refleting or reverberating it: hence it is called a reverberatory. By this difpofition the vapors which rife in the retort are determined more efficacioufly to pafs through its neck. We may judge after this defcription, that reverberatory furnaces are only ufed for diftillations with a retort, in which a certain degree of heat is neceflary. Diftillation may be performed in reverberatory furnaces, cither in naked fire, by placing the retort immediately upon the bars, or in a fand-bath, by placing upon thefe fame bars an iron veflel, in the upper edge of which is a femi- circular cut. Into this iron veflel is put fine fand to the thicknefs of one or two fingers; then the retort is to be placed in it; and, laftly, itis ta be filled with {and up to the arch of the retort. If the heat be required to be of a certain ftrength, the iron veflel muft have a diameter fo much lefs than the internal part of the furnace, that an empty {pace of about the thicknefs of a finger. fhall be left betwixt them, excepting on the fide where the neck of the retort is; and there the hollow cuts of the furnace and iron veflel that correfpond to each other ought to join exactly. See Prat ll. fig.3. ' " ‘The melting furnace, or wind furnace, is intended to produce the, greateft degree of heat that can be excited without bellows. This furnace ought to be fo conftruéted, that a current of air thall conftantly pafs through the fires are piace 3 FURNACE place ; and the more ftrongly and rapidly this. air paffes,, the more iptenfe will be the heat in the furnace. The chief method for producing this effect is, to leave in the upper part of the, furnace a fpace clofe on every fide, excepting above and below ; becaufe the air contained. in this cavity being rarefied and expelled by the heat produced. by the fuel burning’ in the furnace, a vacuum is here formed, which the external air neceffarily tends to occupy from its gravity. nr ah ~ This’ being eftablifhed, the furnace ought evidently to. be fo difpofed that the external air fhall be obliged to enter at the ath-hole, and to pafs through the fire-place, to all the vacuum which is, continually forming both in the in- ternal part of the furnace and in its upper cavity. We ought to obferve, that the column of air which cor- refponds with the upper part of the furnace, being a little fhorter, and confequently lighter, than the column which correfponds with the lower part, the air appears naturally determined to enter at the bottom, and to go out at the top of the furnace; fo that if this furnace was a hollow cylinder, the lower and upper mouths of which were equal, and if the fire-place was in the middle, the air would probably pafs through it from bottom to top; but this difference of the two columns being almoft infinitely fall, the velocity of the current of air would be as fmall : but if, inftead of this difpofition, the furnace be contracted in its upper part, and if it be made to become 2 tube of lefs diameter, then the rarefied air is obliged confiderably to accelerate its courfe in pafling through a ftraiter fpace. and thereby overcomes more eafily the preffure of the fupe- rior air: hence the air introduced through the lower part of the furnace, in order to fill the vacuum which is con- tinually forming in its upper part, pafles fo much more rapidly through the fire-place as it finds lefs obitacle above; and confequently this difpofition of the furnace neceflarily determines a ftrong and rapid current of air to pafs through it, from the bottom to the top. From what has been faid we may eafily perceive, that the more the {pace or- air is rarefied in the upper part of the melting furnace, the ftronger and more rapid is the external current of air which is obliged to enter the furnace to fill up this vacuum ; and confequently the more intenfely the coals muft burn. Hence thefe furnaces pro- duce fo much more heat, as the tube which is at their upper part, called the fube of afpiration, is longer. But vs mu EE — RS————— a a ams FURNACE muft ebferve, that although the adtivity of this furnace is owing in a great meafure to the contration in its upper part or to its tube; neverthelefs a too great contraction of the tube would be very inconvenient, becaufe the air rarefied, and obliged to go out at the upper part, can only acquire a certain determinate velocity: whence it follows, that if this tube, through which the rarefied air is to go out, were fo ftrait that this air could not pafs, unlefs it had a greater velocity than it is capable of acquiring, ¢hen the air, finding an obftacle in its way, would be. retarded in its progrefs ; and confequently too great ftrait- nefs in the tube impedes rather than facilitates the courfe of the air: geeordingly, I have found by experience, that ich too ftrait a tube, however long, lias been adapted, produces little effe@®, compared with a melting. furnace to that caufed by 2 tube of fufficient diameter. Hence the diameter of the tube muft have a certain re- lation to the capacity of the furnace, and to the door of the afh-hole. I have found that the diameter of the tube ought to be to the diameter of the furnace as 2 to 3 nearly, particularly when the tube is long enough. The opening at the bottom of the furnace may be equal in width to the body of the furnace, or it may be contraéted, if the air be required to ftrike the fire with more force and rapidity. After all thefe principles, we now proceed to the conftruc- tion of a good melting furnace. The body of this furnace does not differ from that of a fimple furnace, except that it is, or may be open, Or almoft entirely open below, and fupperted upon feet, or a kind of tripod, which ferves as an ath-hole. An elliptical form is generally given to it, with intention to concentrate the heat ( b). The upper part of this furnace is terminated by a dome higher than that of the reverberatory furnace, called the cap. This cap has two openings, one of which is placed laterally and in the front; it ought to be large, and to be capable of being clofely fhut by a door the other is at the top, and ought to be a tube of a convenient diameter, upon which other tubes of indeterminate length are adjufted. (b) The inequality of the furface of the fides of the furnace would prevent any advantage from the elliptical form, even if heat were fuppofed to diffufe itfelf, like light, only in right lines, and to be thereby capable of concentration by reflection ; a fup- pofition, however, which is not proved. This FURNACE This furnace has ho laboratory, or rather its laboratory is the fire-place itfelf ; for the matters to which the heat is to be applied are placed in the fireplace, and furrounded by the burning coals. The melting furnace may have a door to the fire-place 3 but this door ought to be kept fhut during the operations. It only ferves for the more convenient examination of the condition of the crucibles or other matters placed in the furriace, and not for the introdu&ion of frefh fuel, for which purpofe the door of the cap is intended. This latter door ought to be very large, that a confiderable quantity of coal may be thrown in at once. The reafon why this doof is preferable to the door of the fire-place for the introduéion of the fuel is, that the current of air may not be difturbed in its dire&ion ; and therefore the lateral door ought to be kept open as little as poffible. When the internal diameter of fuch a furnace is 12 or 15 inches, when the diameter of the tube is 8 or g inches, and its height 18 or 20 feet, and when the furnace is well fupplied with fuel, an extreme heat is produced: in lefs than an hour the fire will be white and dazzling, like the fun; its heat will be equal to the ftrongeft degree of heat in a elafs-houfe furnace. In lefs than two hours may be melted whatever is fufible in furnaces (i). The hotteft part of this furnace is 4 or 6 inches above the grate. Chemifts generally believe that the power of a melting furnace is greatly increafed by a wide and high afh-hole, or by bringing the air which is to enter it through a long pipe from without the houfe in which the furnace ftands : but thefe advantages are either imaginary, or only relative to the vacuum formed in the upper part of the furnace. If indeed a furnace be fo placed that the opening of its ath- hole fhall be fitted to the mouth of a great cavity; as toa cave, for inftance, in the roof of which a hole is made, into which this furnace is to be fitted ; and if this cave has no other opening than through the bottom of the furnace; then a very ftrong current of air will pafs from the cave acrofs the furnace, although the furnace had neither cap (i) Mott fufible fubftances may be fufed in a much lefs time 3 neverthelefs we find from M. D’Arcet’s Memoir concerning the effets of a violent and long-continued heat, that by prolongin the ation of fire, he had been able to vitrify fubftances which had refifted the moft violent fires continued only during a fhorter time. nor FURNACE nor tube : but we muft obferve, that this current of air will always be ftronger if the furnace is provided witha dome and tube; and fecondly, if the:air be determined to pafs from the cave acrofs the furnace, even without ‘dome or tube, this muft proceed only from the heat of the furnace rarefying the ambient air, by which the more condenfed air of the cave is determined to: pafs through the furnace to fupply the place of this rarefied: air. Iv this cafe, ‘the’ chamber in which the furnace is. placed ferves' inftead’ of the dome and tube. ‘This happens ina glafs-houfe furnace. Thefe furnaces are built upon:fubterranean vaultsy which ferve as afh-holes.. © The internal capacity of thefe furnaces is very great, and: is occupied. only partly by 'thiei¢om- buftible matters; (and by ‘the pots containing the glhafs: hence the air of the ath-hole is continually introduced there to fill this empty fpace: befides, the heat is always ‘very great in the domes under which the furnaces are built; the contained air is therefore continually rarefied ; fo that they ferve as the domes and tubes of furnacésito.draw the air from the vaults. driv bouag The pipe which is fometimes fitted to the afh-hole of melting furnaces does not contribute tothe draught of the furnace, excepting ‘ the laboratory in which: the furnace ands be {mall and confined : for then the air of this. labo- ratory, being foon heated and rarefied, becomes lefs proper for exciting fire than the colder external air whith the pipe fupplies. See Prarell. fig. 4.5. 6.7. 8.€5 fig. 18. The furnace called the ejay of cupelling: furnace iis of a prifimatic quadrangular figure, and 1s chiefly ufed to make effays of the value of filver, or of filver ores. This furnaceis compofed of an afh-hole, a fire-place, and an upper part which terminates it above, like a quadrangular truncated pyramid, The fire-place and ath-hole are not, properly {peaking, feparated from each other, becaufe this furnace has no grate; hence the coals in this furnace fall to the bottom : in the lower part of the furnace are three {mall doors, two in the fides, and one in the front: above this latter door is a fourth door, placed like that of the fire-place of a fimple furnace; and at the bottom of this door are two iron ‘bars, placed within the furnace horizontally and parailel to cach other. Thefe bars are intended to {upport a muflle, the mouth of which correfponds exactly to the faft mentioned door. In this mufile the cupels and veflels capable of containing the matter to be heated are to be placed. The F URNACE The top of this furnace is truncated, and forms a pretty large aperture, through which the fuel is to be introduced. Some of thefe furnaces have a {mall hole in the front of this upper part, through which an iron red is introduced to pufh the coals down, and which alfo ferves to {hew the fate of the fire. In fome of thefe furnaces the upper part is terminated by a fhort tube, which on fome occa- ‘fons is convenient; for although the internal capacity of this fu rnace, including its upper part, makes a fufficient draught for thefe operationsy a greater heat may poflibly be required, and this is effected by adapting a tube to this furnace. See Essays, and PLATE IL. figs to ome ope jations; which muit be made either in a muffle or in a rever beratory furnace, require the ftrongeft melting heat. The diftillation of Kunckel’s phofphorus; fer in- ftance, requires a heat much fuperior to that of ordinary diftillations. Eflays alfo of porcelain and vitrification, which ought to be done very cleanly, and therefore under a muffle, require a very violent heat, which eannot be procured in an ordinary effay furnace. In thefe cafes a tube may be fitted to the ‘diftilling or to the effay-furnaces, like that of the melting furnace; and thus as ftrong a heat as 1s wanted may be procured. Sz¢ PHOSPHORUS, PORCELAIN, VITRI- FIcaTION. (1). Chemifts have contrived many other furnaces, and fome very complicated, for particular purpofes; but they are moftly embarraffing, ill-contrived, and even ufelefs: for by the furnaces above defcribed an able operator may per- form perfe@ly well every chemical operation: All thefe furnaces may be either portable; and compofed of baked earth hooped with iron rings, or covered with iron plates, if they are intended to be more durable; or they may be fixed and ftationary, and made of bricks and tiles, ‘This depends on the fize and difpofition of the laboratory. The mattet of -all chemical furnaces is always 2 clay, which ought to be of a good quality. Common clays do well enough for furnaces that are not intended to fuftain very violent heats, by which furnaces are apt to be cracked d deftroyed, even before the operation is finifhed, unlefs (1) Ses Prats II.’ where feveral furnaces are reprefented, and the defcriptions annexed ; in which the proper compositions for lining the infides of furnaces made of plated iron, and the methods of applying them, are related Vor. L. Ee they er Bp oS RNs a E A ppg Sng ares NRO, SS EL Le —— ge et RE Be OBEN 32 FUSIBILITY they are made of the moft pure and refraétory clay. See the clays moft proper for this purpofe under the article CLAY. In thefe furnaces no iron bars or {upports ought to be ufed, as that metal is very quickly melted, calcined, and deftroyed. All the fupports within thefe kinds of furnaces ought to be of the fame clay of which the furnace confifts. As the heat is much lefs in the tube than in the body of the furnace, this tube is frequently made of iron plates, ex- cepting its lower part, which ought always to be. made of clay. Thefe tubes of iron plate have many advantages, as they are light and manageable ; but they have a great inconvenience, which is, that their inner furfaces are fub- je& to calcine; hence when much flame pafles through them, fcales fly off from the iron with noife ; which falling upon the crucibles and muffles, difpofe them to vitrify, becaufe iron is a powerful flux to clay. The ae ought therefore to be made of clay. 3) When the tube is long, it ought to be ftrengthened by iron rings and hooks; but thefe ought to be fo arya _that the tube may be lengthened and fhortened, according as the greater or lefs heat may difpofe it; otherwife it might crack. tan The furnaces defcribed in this article are employed, and are neceflary, for the feveral operations of chemiftry. Many of them are alfo ufed in the arts, in manufaétures, and in works in the great: fuch are the furnaces for glafs, pot- tery, porcelain, and for {melting of ores. What is peculiar to any of thefe furnaces may be found under the article of the art in which it is employed. In other refpects. their Gructure is conformable to the general principles eftablifhed in the prefent article. : FUSIBILITY. Fufibilityis a quality which renders bodies fufceptible of becoming fluid, when expoled to a certain degree of heat. Fufibility-is the reverfe of the ality ; fo that the lefs the -heat is which is refraltory qu he fufion of any fubftance, the more fufible tequifite for t it is. Bodies differ much from each other as ta their degrees of fufibility. ~~ Some of them, as air and mercury, are fo fufible that the heat of the atmofphiere is always fufficient to keep them fluid : others, 2s fome oils and water, which are naturally folid with the degree of jcold marked © in Reaumur’s thermometer, are prefently -melted when they + ‘are expofed to a greater heat : other fubftanees again; as lead, tin, bifmuth, &c. are habitually folid in: the ecu; | 4 : natural PU 8S 1T ON natural heats; but are fufible with a d than is requifite to make them red: and dh lon not fufible till they become red, and even white by h Ny fuch are filver, gold, copper, iron, glafs, &c, gid 5 As the fufion of a body is caufed by the interpafition of fire betwixt its integrant parts, by which their adhefion i deftroyed, we cannot conceive any ether caufe of on greater or lefs fufibility than a more or lefs intim contact, and a more or lefs ftrong adhefion of the forte ae pasts of fee bodies ; which are *difpofitions a ng oa the figure of thefe parts, See HARDNESS and FLul= FUSION. Fufion is the ftate of a bod i by fire, See FLuiDITY and F Reta ut bady lena ivg END of the FIRST VOLUME. PR riod, wns Bi a pd 3 a © Se al RR ibn = SA im : i . ss Ht SA [aguce DICTIONARY CHEMISTRY. CONTAINING THE THEORY and PRACTICE of that SCIENCE : ITS APPLICATION TO NATURAL PHILOSOPHY, MEDICINE, AND NATURAL HISTORY, ANIMAL ECONOMY: wi1TH Full Explanations of the QUALITIES and Mops of Action of CHEMICAL REMEDIES: AND THE FUNDAMENTAL PRINCIPLES OF THE ARTS TRADES, and MANUF A.CTURES, DEPENDENT ON CHEMISTRY. TRANSLATED FROM ‘1uE Fi. ACH. . Ww IT H, NOTES, ADDITIONS, and PLATES. THE SECOND EDITION, TO WHICH 1S ADDED, AS AN APPENDI X, A TREATISE an the Various Kinds of PERMANENTLY EL ASTIC FLUIDS, or GASES. vV OL. 1 Bertram saat? : L ON D.O N; Printed for T, CaDELL, and P. ELMSLY, in the Strand. MDCCLEXY1Iy WA { }-e Pvp don NH : ere dH RT A DICT ILONARY OF CHEMISTRY, GALLEY ALANGAL. (a) : (G5 GALBANUM (3) kre oT GALLEY. This name is given to reverberatory furnaces, in which feveral retorts may be placed at the fides (a) Garancar, The Indian root called greater galangal re- fembles ginger in fmell, tafte, and chemical compofition. The fmaller galangal has a ftronger and more agreeable {mell than the former, and a more pungent and hot tafte, like that of pepper. From 16 ounces of this root fcarcely two f{cruples of oil were ob- tained ; and this oil poffeffes little of the pungency of the root. Six ounces of extrac were obtained by means of water from 16 ounces of the root; and an ouncé and a half from the fame quantity by means of fpirit of wine. The watery extraét was the more pungent of the two. Newman. (2%) Ei sanv a is a gum-refin, containing more of a refi- nous than gummy matter. Spirit of wine extracted from a pound of it nine ounces and a half, and water extracted from the {fame quantity only three ounces. The {mell, flavor, and peculiar tafte of galbanum refidesin an effential oil, which may be raifed in diftillation either by means of water or of fpirit of wine. * From a pound of galbanum fix drams of effential oil may be ob- tained, This oil, or a great part of it, is of a blue color, fometimes of a deep bright blue. ‘By expofure to air this blue color is changed to a purple, Newman. Vor. IL B of V365072 Ph . ty b.. Pr d + «© i Eo b | b immmismimalGhedield, 7 a or 4 ? naa —_—— o_o —n i. of each other. As thefe furnaces ar id have late C0 other. As thefe furnaces are oblong, ‘and have late- Fil openings,-they-have been oppor to jefemble alleys and have thence received their name. ’ GALENA. ¢) i GALLS. (d) : Ah GAMBOGE. \ (c) GALEwa ‘is the name of a lead oie oh ing’ particles, and com pofed-of lead inefalifediby Pe ul oh io a little filver is almoft always united. See Ores oF Leap (4) Garis are excrefcences found upon oak trees, and are Among the firongeft vegetable'aftringents. Extras made from galls, either by water or by fpirit, poflefs all the aftringency of s ele vegetable fubftances. From fixteen drams of galls fourteen ; ay were extralled by water ; and from the A quantity : id Ye Srafs and ‘two feriples were extracted by fpirit. Galls, 3 other vegetable aftringents, or the infufions of thefe fub- ances, being added to folutions of green vitriol, or to dilute And faturated folutions of iron in any ‘acid, “change. the colosaf thefe folutions to a deep blue or black. The black liquor thus produced is the bafis of inks, and of many black dyes. See Brack and Ink. - When the green vitriol is diffolved, and when the galls are infufed in diflilled water, or in common {pring wa- ters, the color produced by mixing .them is; according to-Dr Lewis, blue: but if the fmalleft postion of alkaline falt be dig {olved in the water, or if this water has any putrid tenflency, however ‘{mall, the color’ produced will ‘Be: parplifh ‘or reddit. Thefe colors, when rendered more ‘intenfe; by adding more of the Solering fubftances to the water, appear black., The blacknefs proc anced ‘by ‘this hixtiite prcetds from a ‘colérin matter which is only diffufed throngh'the liquor, and may baa parated from thence by dilution with'water, and by depofition,- I'he feparation may be prevented, as'is done inthe preparation of ink, by adding “fome mucilaginous matter, as ‘gum arabic This cclored matter is evidently a ferruginous precipitate ; for altho’ it cannot be attraéted by a ntagnet, this property ma be given to 1t by a flight calcination. = To this precipitate fone of the inflammable matter of the vegetable aftringent adheres and gives color. When by calcination this adhering matter is made to combine in fome meafure with the ferruginous precipitate, this ‘precipitate, though not’ perfeétly metalized, is however fuffi- ciently metallized to be rendered capable of being attrated by a magnet. In thefe properties this precipitate corre!punds with the blue ferrugisous precipitate, which fornisPruflian blue, to which alfo fome phlogiitic matter adheres and gives color ; but it differs from Prufiian blue by this property, that ‘it is foluble by a. ge whereas the latter precipitate is not foluble. “Thus A coloring matter of inks may-be diffolved by acids, and their co. : i ker, did lor which are fo intimately‘blende © part ‘of it is foluble either by water or by fpirit of wine. "It i i i) i a Wl LH GARNET GAMBOGE. (¢) GAN GU E. Gangue is the matrix of ores. See Ma- " TRIX. Sn 0, 7 ind : GAR “o & ! ' lor thereby deftroyed.” Alkalis alfo deftroy the blacknefs of inks, by diflolving the aftringent or inflammable adhering matter, and leaving’ the iron in an ochéry flatey fimilar to the precipitates of iron, formed by adding alkalis tofolutions of that metal in acids. The blacknefs deftroyed ‘by adding acids to ink is recovered by addition of alkalis 3 4nd converiely, I have not found that galls precipitate ather, metallic {ubftances; ‘but I have obferved, that when added to metallic {olutions, the precipitates afterwards formed from thele by fixed alkalis, ‘were deeply colored, and generally purple. (2) Gameogke is an acrid um-refin, the gummy parts of 5 with the refinous, that greateft Forms ‘4 beautiful yellow ‘pigment, and’ is'méch ufed as fuch by painters. Dr. Lewis fays, that it gives a beautiful and durable citron: yellow fain to'marble; whether robbed in {ubltance on the hot fone; ‘or applied, as Dragon’s blood fometimes is, in form of a fpiritaous tinéture. "When it"is applied on cold marble; the tone is afterwards to be heated, to'make the color penetrates “('7) Garric. The roots of ‘garlic consdin a confiderable quantity of mucilage, fome refin, and a very fmall portien of effential oil, in which the whole finell, tafe; and peculiar quali- ties of garlic refide. From thirty-two ouncesof garlic diftilled with water, Neuman could obtain fearcely ‘half ‘a dram of this oil. Ti (g) GAarNET, Granatus gemma, is a fone ranked amongft thofe ‘¢alled gems, ‘tho’ lefs brilliant than any other gem ; it is- tranfparent, {ometimes more and for-etimesilefs ; generally of a dark-red color, but fometimes yellowifh or brown; the eighth ftone in hardnefs from diamonds; and fufible by fire. Cron- fedt forms a diftinét order of the garnets and the bafaltes, which he calls terre granate.” The diftinguifhing property of theife garnet earths is, that they are'more fufible in proportion as. they contain lefs metallic matter, and are more tran{parent and glaliy in their texture. In other refpeéts they refemble the filiceousor- der of egrths. See Basartes. = All garnets contain iron j molt of them contain tin alfo; and fome, according to Mr. Swab, contain iron and lead. Their forms are varions ; fome having fix fides, and others having a greater number. To imitate garnets, ‘Neri dire@s, that twenty pounds of eryftal frit, fixteen pounds of '¢alx of lead, three ounces of mangancfe, half an ounce of Bz . zaffre, -~ . " _". . 3 mes - 2 ER RN Pr r— g ri eg RE ro en cect mrss: ———— a A Es ses a I hr ———————— el LT) GAS G A S. This name is given by chemifts to the volatile in- vifible parts which efcape from certain bodies, and which cannot be retained and collected, atleaft without great diffi- oly and mixture of other fubftances. hus, for example, the noxious vapors which rife from - burning charcoal, and from matters undergoing the fpiri- tuous and putrid fermentations, the volatile part of {pirituous mineral waters, the fpiritus reCtor of fome f{ubftances, fuch as mufk, may be called the gas of thefe bodies. The gas of moft fubftances, particularly thofe which affe& the nerves, feems to be nothing but pure, or almoft pure phlogifton, which is intr s from bodies without igni- ~ tion. The mineral noxious vapors called damps may be alfo ranked amongft vapors called gas, at leaft thofe of them may which are invifible, Sez Dames. (4) GELATI- zaffre, fhould be fufed fogether during twelve hours ; and that the vitrified mafs, after it 1s feparated Bons any lead which may have been revived by the fufion, muft be again kept in fufion during ten hours. (5) Gas. This word is derived, according to Junker, from the German Gafebt, which fignifies a frothy ebullition, as many of the elaftic fluids to which the name gas has been applied, as the gas of effervefcing and fermenting fubftances, are atthe time of their production, accompanied with many bubbles. The word is applied by Van Helmont to fignify thofe elaftic fluids which are invifible, and not condenfable by cold, feveral of which he has obferved and defcribed. Such are the gas wentofum, or at- mofpherical air; gas fylvefire, or the fluid expelled during fer- mentations and effervefcences, called by later authors, fixed, fac- titious, and fixable air; gas pingue, or the fluid extricated from inflammable fubftances during their analyfis by heat ; gas flam- meum, or the fluid produced in the deflagration of nitre. He confiders alfo, as fo many kinds of gas, the noxious fluids which hover over the grotto del Cane, and at the bottom of mines and cellars 3; and that which arifes in the Jurning of charcoal. The fubject of permanently elaftic fluids has been further cultivated. with great fuccefs by Boyle, Hales, Black, Macbride, and Caven- difh, fo that it is become an important branch of natural philofo- hy, fo intimately connefted with chemiftry, that without a Eedze of it, a great variety of chemical phenomena cannot be underflood. ‘It has however, been little attended toabroad till within thefe few years. The author of this Dictionary, who has treated fo copioufly and perfpicuouily all the other {fubjeés rela- tive to chemiftry, is almoft entirely filent on this head, and feems to have been, at the time of publithing his work, unacquainted with thin layers of gold upon t GILDING GELATINOUS, and GELLY. (i) {dine is the art of applying exceedingly ian : et PE an fubftances, i ternal appearance of gold. : #2 he Dattre ty > Pod bave 0 : tioned foven) ene .f v4 . ifferen: uiries and difcoveries concerning he TE : it to different fubftances. Flence tHE, : es aft eg and contains many particular opera ti d various management. 5 Bt ood is given by pamnfin wd farniken ithout employing * ; but this 1s 2 falfe ki 9 grog Thus a very fine golden colour is given to brafs ig ’ 9 Sysingugen el mes EET wl being tranfparent, fhews all the brill a ornaments of brafs are varniinec 1 © ph, 2% called gold lacquering, £0 diftinguifh them from thofe which are really gilt. Silver-leaves thus varnifh- with the late important difcoveries of Dr. Black and be iin dith. With a view of fupplying this defect, anote was iu em : the article Air, in the fo dition of this rillan [pling "of the principa | ently ABS A sbierved. Sinpe that time, a great vaslety of Spe ans and obfervations have been Jade py. DT Te Lay . fo that a revifal of the ™ Se ie not being compleated at the time of ny this fheet to the prefs, the account peopeiey 2 be § lang] fhe was ri ind as, or permanently € ) ; WA fas Pree, but will be added {eparately as an ‘Appendix. = Ar GeraTinous and GELLY. See JeLL¥. (#) Gews are certain ftones confifting of the init, 8 vag ly ¢ tri lued ss improperly called witrifiable earth, much valued > ay color, hardnefs, weight, ad, ratlyy. | Pliele ake, diamonds, rubies, faphirs, topazes, emeralds, chry } Sy die thyfts, garnets, hyacinths or jacinths, beryls - que jer) 55 The order in which they are enumerated fhews eir 3 Bethe grees of hardnefs. See each of thefe articles, 11am > MO Za an. From fixteen drams of hg root of geen Neuman obtained fix drams and a half of refinous 2 ’ a by means of {pirit of wine, which contained all the hiner gine wentian : and from the fame quantity he obtained sine rams of ummy extra®, which was confiderably bitter, but leis , the fpirituous extradts Bs ed EE ag A GILDING, ed are put ich i i fe a ii leather, which is then called gilt leather. Amongft the falfe gildings may alfo be reckoned thofe which are made with: thin leaves of copper or : W s.of copper or brafs,, called calle i Yi manner are made all the kinds of what is n the true gilding, gold is applied to the furface of bodie fae gold intended for this purpofe, aught in rl iy be eat into thin leaves, or otherwife divided into very fine parts, ; As metals cannot adhere well merely by conta to any ut to other metallic fubftances, when gold is to be ap; lied to the furface of fome unmetallic body, that furface 1 be pravieufly covered witht fome gluey and tenacious fubftance by which the gold, {hall be made to adhere. Thefe fub- anges are. in general called fizes, Some of thefe are made vegetable and animal glues, and others of oily, gluey, and rying matters. | Upon them the leaves of gold are applicd ; and when the whole is dry, the work is to be finithed and polifhed. Waod chiefly is gilt in this manner; but it muft be previoufly covered with ten or twelve layers of chalk mixed with glue difiolved in water. That forms a bod ; or coat, which hurts the fculpture and mouldings upon the wood ; butis neceflary for furnifhing the gold with a fofter {upport 3 otherwife, if the gold was applied to the wood with- out the interpofition of this fize, it would be apt to be torn and rubbed off, when ‘burnifhed, that is, polifhed with a hard inftryment, called a dog’s taoth, to give it Tuftre. (m) - The (2) When wood, paper, and fuch fubftances a Je of they muft be Ad Sl dh with fome tints be Ee upon which, when. almoft dry, gold leaf is to be applied and prefied down with a little cotton, or hare’s foot. When the matter is dry, the gold is to be burnithed. When the work is - required to be capable of refilting rain or moilture, it ought to be previoudly covered with a compofition of drying oil and yellow ochre ground together; otherwife a, water-fize may be ufed, which 1s prepared by boiling cuttings of parchment or white leather in water, and by mixing with this fome chalk or whiting"; feveral layers of this fize muft be laid upon the wood, and oo thele a layer of the fame {ize mixed with yellow ochre. “Laflly; another mixture, calied gold fize, is to be applied above thefe ; m hi C ¢ p ! Thi ( y upon which the gold leaves are to be fixed. This gold fize, the ’ es { : d . ,ufe of which 1s to make the gold leaf capable of being burniflied, is compofed of tobagco-pipe clay, ground with fome rudd! Y¥i Ts ’ co black lead, and tempered with a little tallow or oil of liver, miwplend AGU Lie Ea ooh “leaned ; and then leaves are to be applied to it, means af rubbing. with 2 poki yore. ni «fhe method of applying gold upon metals is entirely dif- ferent. The furface of the metal to be gilts firft to be x which, by {hed blood-ftone and a.certaida heat, are made to adhere perfectly well. (n) Gold is applied to metals in feveral other manners. One of ‘thefe is by previoufly forming the gold into a pafte of amalgam with mercury. See AMALGAM. hale With this amalgam the futface of the metal tobe gilded is ¢6 be covered 'j then a fufficient heat is to be applied to eva- porate the mercury; and the gold is laftly to be burnifhed with a blood-ftone. (2) Final : inally, egree of The edges of glaffes may be gilt by applying, firft, a very thin coat of varnith, upon which the gold leaf is to be fixed ; and when ‘the varnifh is hardened, may be burnifhed. This varnith is prepared by boiling pewdered amber with linfeed oil in a bras veflel to which a valve is fitted, and by diluting the above folu- tion with four or five times its quantity of oil of turpentine; and that it may dry fooner, it may be ground with fome waite jead. (#) In this manner filver leaf is fixed and burnifhed vpca brafs in the making of whats called French plate, and fometiracs alfo gold leafis burnifhed upon copper and upoy ron. {o) This method of gilding by amalgamation 1s chiefly ufed for gilding copper, or an allay of copper, with a {mall pcrtion of zinc, which more readily receives the amalgam, and 1s allo pre- ferable for its colour, which more refembles that of gold than the color of copper. Of the method of preparing the amalgam of gold, fee the word AMALGAM, The proportion of mercury to gold is generally as fix or eight to one. When the metal to be gilt 4s wrought or chafed, it ought to be previoufly covered witi quickfilver, before the’ amalgam is applied, that this may be eafier fpread : but when the {urface of the metal is plain, the amalgam may be 2pplied directly to it. The quickfilver or amal- gam 1s made to adhere to the metal by means of a little aqua- fortis, which is rubbed cn the metallic furface at the fame time, by which this furface 1s cleanfed from any ruft or tarnith which might prevent the union or adhefion of the metals. But the ule. of the nitrous acid in this operation is not, as is generally fuppoi- ed, confined méfely to cleanfe the furface of the metal to be gilt. from any rut or tarnifh it may have acquired ; but it alio greatly facilitates the application of the amalgam to the furface of that metal, in the following manner: It firft diffolves part of the mer- cury of the amalgam ; and when this {olution is applied to the ¢coppeg, ‘ this latter metal having a fironger difpofition to unite with the nitrous acid than:the mercury has, “precipitates the wei -, gury upon its furface, in the fame maoner as 2 polifhed picce off B 4 a : ron GILDING Finally, fome metals, particularly filver, may be gilt in the following manner ; Let iron precipitates upon its furface copper, from a folution of blue vitriol. = When the metal to be gilt is thus covered over with a thin precipitated coat of mercury, it readily receives the amalgam. In this folation and precipitation of mercary, the principal ufe of the nitrous acid in the procefs of gilding appears to me to con- fit. The amalgam being equally fpread over the furface of the metal to be gilt, by means of a brufh, the mercury is then to be evaporated by a heat juft fufficient for that purpofe ; for if it be too great, ;part of the gold may alfo be expelled, and part of it will run together, and leave fome of the furface of the metal bare : while the mercury is evaporating, the piece is to be, from time to time, taken from the fire, that it may be examined, that the amalgam may be fpread more equally by means of a bruh, that any dofettive parts of it may be again covered, and that the heat may not be too fuddenly applied to it: when the mercury is evaporated, which is known by the furface being entirely become of a dull yellow color, the metal muft then undergo other opera- ~ tions, by which the fine gold color is given to it, Fort, the gilded piece of metalis rubbed with a fcratch-brufh (which is a brufh compofed of brafs wire) till its furface is made {mooth ; then it is covered over with a compofition called gilding wax, and is again expofed to the fire till the wax be burnt off. This wax is com pofed of bees-wax, fometimes mixed with fome of the followin fubftances ; red ochre, verdegrife, copper-fcales, alum, vitriols, borax, By this operation the color or the gilding is heightened ; and this effe® feems to be produced by a perfect diffipation of {ome mercury remaining after the former operation. . This diffi- pation is well effefted by this equable application of heat. The gilt {urface is then covered over with 2a faline compofition con- fitting of nitre, alum, or other vitriolic falt ground together and mixed up into a pafte with water or urine. The piece of metal thus covered is expofed to a certain depree of heat, and then quenched in water. By ‘this method its Sp further improved, ard brought nearer to that of gold. This effe&t feems to be pro- duced by the acid of nitre (hich is difengaged by the vitriolic acid of the alum or other vitriolic falt during the expofure to heat) alting upon any particles of copper which may happen to’lye on the gilded furface, Laftly, fome artifts think that they give an additional luftre to their gilt work by dipping in a liquor prepared ‘by boiling {ome yellow materials, as fulphur, orpiment, or turs meric. The only advantage of this operation is, that a part of the yellow matter, ay the falphur, or turmeric, remains in fome of the hollows of the carved work, in which the gilding is apt to be more imperfe®,’ and to which it gives a rich and folid ap- pearance. HT ent a Leg plied to the furface of the glafs. ® Ie ' ' EE GILDING ed : : : 1 wt old be diffolved in aqua regia. Is his eludes Si To Eure to be dipt, and burnt to black afhes. Thele of linen are ubbed on the furface of the Sy “hev coire afhes betsy; x apply the particles of gold w ie ! Th vos wet hen hich by this method adhere very hi) the tain, an wr of the afhes is to be wafhed Olt § & joer to be pris pe lver, which in this ftate does x i acauire a ficgiof the 4 Duarnithed with a blood-ftone, till it 9 and gil, 1510 be old. This method of gilding Mott = yy ne color ik ‘fmall ‘quantity of old. Mo Ct? much confumes 2 lo {nuff-boxes, an odie? toy a pr and little value, are nothing but diver git 1 TZ 0 : Se ' ol i d other manag. lied to glafs, porcelain, an . Go may slo be 00 is of thele a it Wa, Pusfhed pr confequently % capable of A Tih foie . vo " a . . pa i Je Hd illic nature. This gild- orce, 1d is more exactly ap- ing is fo much more perfect, as the go ote oe aoe i it is faid, it ilt by amalgamation, unlefs, as it 1s t gos foul oS oh his by dipping in 2 fointion of Hs I ay alfo receive a golden coat from a {atu pred 0} A. pry ua regia, mixed with fpirit of wise, id Jai BE eeier Snity with the acid, from whict 3 9 refone i E he old. ‘Whether any of thefe two me ols Semp i fe fo not know ; but the method com agely em of fixing gold upon iron B at: above-met Sued, of ifhi - this metal w reins Ew en will be more perfect, if the furface Cpe revioufly {cratched or graved. ¢ pilin. oR has bet h P method is mentioned by authors © 8 Br Se 4 alfo upon earthen ware, and upon glais 3 which is 52 be old ith regulus of antimony, to putverize the Hl Lh fics a brittle to admit that operation, 9 p Sa is fu A iece to be gilt, and expofe it to fuc! BE der Pe evaporated, while the gold jesaaine BR The + yegulus 22 ios of this method, according to uals, 21%, an, owder does not adhere to the piece, asd ugk 2 i by Gread : that part of the gold is difippted a ng With fe ots Fhat glafs is fufible with che heat nece ey £5 the ois [ 1 f f antimony ; Qe Be RE wi have ts furtace rendere even. ! - expofed am " A —r—————_ tac oe i] \ GIL:ACILE expofed to a certain degree of heat; and burnithed fighiei y to give themy luftre; (p) - 1a « 1Thefe are the principal methods of gilding. Silvering'is perforinéd by procefles very: funilar ‘to thefe, and founded on the fame principles. - 7) GILLA VITRIOLI. "This name: is given to white vitriol... purified . by cryftallization, which was formerly given as: an emetic, from half a fcruple to a dram, See ViTRIOL. ; : on GINGER. (7) GLACIES MARIA, (5) (#) A'more fubftantial gilding is and porcelain, by applying to ‘thefe mixed with a folution of gum. arabic, and a {mall quantity of borax, after be applied to foften the glafs'and th burnithed, With this mixture any fi powders for this purpofe may be made, 1. By grinding gold leaf with honey, which is afterwards to be wathed away with water ; 2. Byditlling to drynefs a {olution of gold in agna regia; 3. By evaporating the mercary from an amalgam of gold, taking care to fiir well the mafs near the end of the procefs; 4. By pre- €ipitating gold from its folution in aqua regia by applying to it a folution of green vitriol in water, or fome copper, and perhaps fome other metallic fubftances. (7) Silvering by amalgamation is feldom prattifed, as it does not fucceed nearly fo well as the gilding by amalgamation. The common method of filvering metals, as brafs, or of makin French plate, is that mentioned above of - burnithing filver leaves, from twenty to fixty, upon the piece of metal previoudly ‘heated. on (7) Gincer. From fivteen onces. of the root of common ginger, about a dram of oil poflefling the fixed upon glafs, enamel, fubftances powder of gold or with fome eflential oil, which a fufficient heat is to e gold, which is then to be gures may be'drawn. ‘The I us extract, containing all the pungent, matter of the root. “Water alfo extracted four ounces from fixteen ounces of the root. The watery extract was confiderably pun-. gent, but it feems to receive its pungency from fome part of the refin which is mixed with it ;- for the refin Temaining in the. root after the extraction by water, contains greateft part of the pungent matter. Neuman, (sy Gracres Marra, laminated, felenitic Gyrovym. Its app or lapis Jpecularis, or gypfequs ftone. carance is very fimila is a tranfparent, For its properties Jee I to that of talk, but differ GLASS . b=. Glafs is a hard, folid, brittle, tranfparent fib-. GLASS. fifts, when it is of a good quay Yor al it is ftance, Tere acids and all other menftruums., 4Y> of air, water, 3 yi {trong heat. Ng i "he ng any of vi earth which enters into e la : » t hen itis pure, thatit :« (o difficultly fufible, when f our fur-~ 3 this g2f this fo di vitrified by Fs ps fees be mixed canno nd particular’ > intimate. naces ; en Ir Fufion is fellitatedy 2nd. fo er with it, Dy that it makes with them Df f olafs. an on formels enter into the cqmpofition. of 2 the ve here the definition o Bl hl im. ne oy oR tarioN for what we have to 1ay artic ; : - portant fub ect. ANTIMONY. The method, of . pre Gl As 4 antimony, 1s by calcining, il Lo rife, and paring g oa ate heat till no more vapors o h In This with 2 mo s gills to a grey ath-colored peat = ood melt- till it be re he be put into a crucible, place ine a applied Ca ns and a fuficiently ftrong heat is ather ill it be ing furnace @ or an hour and an half, or SR, may be during od into a tranfparent glafs. he > iron rod into an have been well mad bY, pA will adhere now! e vi : : hat cafe, {ome drawn ER TTR 1 Ce coon to the = es wire, like ordinary glafs. Tafs is to be caft up~ Fi ken from the furnace, and the SF to have been pre- 2 bi plate of copper, hich aug’ i when cold, or it perfectly. or yiouy hose Hy actuthine color, more or lefs yellow is of a | ; ' fufion reddifh. etallic matters are difpofed to fan - The enh of ail se they fill retain a portion of Bs Li on Hy py If this portion be too er and more Rammgable prt eafily ; but the mafs will bs Wh trary, be mel roading the esallie Bas. 35 Sy are fo much or leis j hlogiiticated, Ce ey hes ot me f thts Plog more re ? . At hich talk J Se hat the ples of which, Ns it in this circumftance, that the pa: nflexible, giffers fom exible, while thofe of Qe boda] fo and onfifl £ thefe laminated gypfums have 2 CH have no deter- Pee then called felenites, or gyp/eans 7; are i ; ’ and minate form, * es Ens sea ¥ | Aq bf ¥ EN ig | i D. GLASS gnd at 1aft become entirely unfufible, at leaft in the fires of our furnaces, when fo much deph only the properties of pure earths. Therefore metallic glafs ought to be confidered as ina flate intermediate betwixt that of metals and of earths. Accordingly the glafs of antimo- ny, like all the others, is fo much ‘more colored, fufible, heavy, and lefs tranfpagent, 3s the antimony employed has "been lefs calcined. i Pa ; As glafs of antimony is chiefly prepared for the purpofes of medicine; and as its emetic ‘quality, which is its chief virtue, depends on the quantity of inflammable principle which it retains ; this glafs, tobe well conditioned, ought to be moderately fufible and tranfparent, of a hyacinthine color, not too clear, nor too deep; laftly, it ought to fmoke, while it remains fufed. When the glafs is poured out, this fmoke condenfes partly in white flowers, which fix upon the furface of the glafs and upon the plate of copper. © Hence the eflential point for making beautiful and good glafs of antimony is, to give the antimony the precife degree of calcination which is neceflary; which. is not very eafy, Accordingly the operation fometimes fails ; but the excefs or defect of the calcination may be remedied. If the calx be too fufible, and if it flow into a fluid matter which is not = tranfparent, nor is capable of being drawn out into wire, as glafs is, we may conclude that the calx has not been fuffi- ciently calcined. In this ftate, the fire ought to be dimi- nithed, the crucible uncovered, and, after the matter has ~ been allowed to fmoke during a certain time, the fire ma be encreafed, and a tranfparent glafs will be obtained. But if, on the contrary, the calx cannot be made to flow or vi- trify well, this fhows that the calx has been too much cal- cined. This fault may be remedied by throwing into the crucible about a fixteenth part of the weight or the calx, of crude antimony, and then fufing the whole. This fmall quantity of crude antimony not only gives phlogifton to the calx, which thereby becomes more fufible, but alfo fome mineral fulphur, which produces the fame effect ; for glafs of antimony feems always to retain a certain quantity of fulphur. When the calx of antimony employed for the preparation of this glafs is evidently of difficult fufion, a very ftrong heat ought to be applied quickly ; for by being kept long moderately hot in the crucible before it is fufed, it is more and more calcined, and at laft rendered unfufible. Some calxes are fuppofed to have been tao much calcined for this operation, . ¢ logifticated as to poffefs GLASS tion, becaufe they were not expofed to ftrong fire fuffi- -operatioily ciently quickly is more eafily and perfe&ly foluble in Sus Tuy in oily ids, than the regulus; mousy Ph taken internally, it produces more con- YR as an emetic: For this reafon alo, it is ae it cream of tartar for the preparation of fibiated combi. Quai S/T i icinally without other prepara- Forme gE or been fe) nis by i violence and uncertainty of 1 prodene mi the fame caufes as thofe Lo ic vende? the article TARTAR (EMETIC). Never e- Er -ven with fuccefs by very able phyficians in bre Sg the colic of miners. But notwithftanding th: Silanes worst h has eftablifhed the ufe of it in thefe cafes, wo; ie tartar might be adminiftered with equal fuc- po ter certainty; and, if neceffary, in more fre- hs Lager dofes than in ordinary cafes. See TARTAR que (EMETAds of ANTIMONY CORRECTED ly A method has lately been pradtifed in Englan hifi the olafs of antimony milder ; and this preparation. a Ended as an excellent remedy in dyfenteries, poo rE rr aags". It is made by melting a dram of yell ” ax in an iron ladle, and by adding to this an ounce g Ee lafs of antimony, in a fire continued during a a juft trong enough to diffipate almoft en- . ly the wax without inflaming it. When the fae is Sod :¢ appears of a brown color. Itis again to be levi- py d tied the glafs of antimony corrected by wax, Fo. ceratum antimonii. The dofe of it is from fix grains to ten or twelve. hinleap iran eti f glafs of antimony 1s inde I a the wax evidently furnifhes : yin ery of phlogifton, and approximates it more Ee tue he of the regulus, or rather of Se piss o aotenys i etic than the glafs. Butt bs A 7 be fubjed to the inconveniencies of thefe pais reparations of antimony, particularly to fhe Ineqiz- Tic oF their effets, and for the fame reafon. By introd ro this new remedy, therefore, 2 kind of pispargiion eleatially faulty, and setinquilied Fo a oh ras again been brought into ule, withou 3 Shen the difeafes, for which it 1s recommended, proceed from oro a a—— dk NO] GLASS caufes, ang ought not to be treated with the fame remedies ; as Mr. Baron has judicioufly remarked in his ‘edition of Lemery’s Chemiftry. GLASS of BORAX. Borax is, as we have faid under ‘that article, a neutral falt, which when expofed to fire, lofes the water of its/ cryftallization ; and by a ftronger heat is further fufible into a matter which may be drawn out, ‘while hot, “into wire, like ordinary glafs ; .and which, when cold, has the appearance of a very white, tranfparent glafs. Bo- rax thus perfectly fufed has been called a glafs, from its re- femblance to vitrified matters, This glafs of borax differs neverthelefs from true glafs by the faline properties which it retains ; it being entirely foluble in water, and again cryftal- lizable into its original form of borax. It is fufceptible of the fame decompofitions as borax ; in a word, it does not differ eflentially from borax, but only in being more dry, or deprived of water. To obtain very beautiful glafs of borax, it ought to be uarded againft athes and coals, which is conveniently done by melting itin a muffle. As this matter is very fufible, and at the fame time capable of facilitating much the fufion and vitrification of fand, and other earthy matters, it is advan- tageouily ufed in the eflays of ores, and as an ingredient in compofitions for glafles and artificial cryftals. But for this latter purpofe a very fmall proportion only ought to be ufed, as. it imparts to glafs the fame property it hasitlelf, of lofin its luftre by expofure to air, Glafs of borax is preferred to borax for thefe purpofes 5. becaufe it is deprived of all fuper- fluous moifture, and is not fubje& to fwell, as the borax is. See Bor AX. GLASS of LEAD. Lead is ametal eafily calcinable ; but it has a fingular property, that when it has loft fo much of its phlogifton that it cannot be reduced into metal without addition; it then retains the remaining part of its phlogifton . more ftrongly than any other metallic matter. Hence cefufs ‘or white lead, minium, litharge, and all the other prepara- tions and calxes of lead, retain always great fufibility, and are much difpofed to vitrification, All thefe matters, by a mo- derate fire only, are eafily fufed, and formed into a tranfpa- rent glafs of a deep yellow color. But this glafs is fo pene- trating and fo powerful a flux, that it pafles throngh crucibles as foon. as it melts; and when it has been kept long enough in the fire to be perfectly fufed and vitrified, none of it is to be found in the crucible, which is then glazed over internally and externally, This & LASS i v of lead proceeds from ifs powerful syThipmapertyob Blof Ot by. which it difpofes ho £2 api "P Hence the difficulty of obtaining a pure gla : 8 mietity. renter -confiftence ‘muft be given to it an jis pre suk. be seprefled by aig with:fandy in't AA A ror. t3 it fit for ufe. following manner; $8 onder HN minium for inftance; and pod ake OO ompowdered #flints. + Put this mixture inte nes paKe b ible made of. refractory clay, ‘baked into a very ai good pri Place i this crucible in a melting furnace, sompackbo Joid .t well with a luted lid. . Thiscrucibleis Re by degrees, and very flowly ; not only io Ph piens 40; Li of -the crucible, to which this kind o erst i the, A eid when heated 'too quickly, but to hindert e ar ol welling too much, and flowing over the cruci= i rind ion. During an hour or an ‘ble. in the beginning of the fufi g ; re muil be thus managed in the be= boss 0 ah a afterwards it may be encreafed, Spa ompleat fufion, and continued in that ftate dur- A 7 ‘a half ; after which the crucible i EA the furnace; ‘and when it ta Beokes, a viry in yellow colored glafs is found v it. 3 wom és Lifts. direct. the addition of fome nitre an £0 0 or above mixture, as thefe falts promt the fufion, an me al diftribution of -the fand. : mote enue] SitEbeeOn ‘we. have feen, is not a pure glafs of vin Be in which the lead is-the prevailing ingredient, has a confiderable fpecific gravity, and its OWE vg he heavielt. As it is very fufible, and ealily ¢ re bdr : moderate fire, and as it is befides a very poweriu Aux, it is A natal employed in effays of ores to faci itate their fcorification. See Leap and ¥rzassrearson; & js . GLASS-GALL. This 1s2 faline ae; rym as a fcum’in the pos of arpcies Lap pe, Py A This matter is chiefity comp wie a mon falt, vitriolated tartar, ar feng: heaira an fot enter into vitrification, and ps hss) sgl} on tained in the afhes or alkalis employed in 1 % pol jolt for © Glafs-oall is ufed to facilitate the fufion n go a in effays ; but this matter muft vary J A ing to the kinds of alkalis or athes from w duced. (1?) GOLD. (t) Glafi-gall, called allo Sandiwver, is faid to contain the vi- AF F ’ elie, ne. OB as em lo ed in the com- griolic acid, although no vitriolic falt'w ploy pofition GOLD GOLD. Gold, called alfp by chemifts the Sun, 8o/, and the king of metals, is a perfect metal, of a yellow fplen. did color, and unalterable by all the operations of art, his is the moft perfe& of all metals ; its principles are the beft combined, and it poflefles moft eminently the metallic cha ralteriftics. When gold is ve pure, it has no tafte nor {mell, even when heated and rubbed. It lofes in water betwixt >5 and J, part of its weight. A cubic foot of gold weighs X326 pounds. It is the heavieft of all metals, and confe- quently of all known bodies. ‘he hardnefs of gold js intermediate betwixt that of the hard and of the foft metals. Its ig is furprizingly great, and exceeds that of all metals. From calculations ‘made by experimental philofophers concerning the extenfion of gold upon filver, a fingle ounce of gold, the bulk of which is very fmall on account of its great weight, is found to be capable of covering and gilding perfedly a filver wire 444 leagues in length. he gold-beater’s art, by which gold is formed into {uch thin leaves that they are made to float in the ajr by a light breath, is a further proof of its great Justify, and is alfo a proof of its extreme opacity : for thefe gold leaves are fill perfectly opake. Light may indeed be perceived through them; Lr this is owing to cracks, which may be eafily per- ceived upon examining the leaves, and which are occafioned- by the repeated ftrokes of the hammer, When when violently comprefled, as it is by gold-wire-drawers, pofition for the glafs, The vitriolated tartar which is in all ot- ath and wood-afhes employed in the manufadure of glafs, might account for the exiftence of vitriolic acid in common glafs-gall ; but Pott affirms, that by melting together fixed alkali, flints, and common fal, a falt of Glauber may be produced, which he thinks very fimilar to glafs-gall in many of its properties ; but from which, however, it differs in this, that 326 gall deliquiates b expofure to air, whereas the falt of Glauber falls into a dry pow- der. Tachenius fuppofes that the vitriolic acid of glafs-gall pro. ceeds from the flints, Its cryftals refemble, as Mr. Port ays, partly vitriolated tartar, and partly the falts of mineral water. It differs from vitriolated tartar in being more fufible, more folu.. ble in water, andin being even deliquefcent. It is ufed as a flux in eflays of ores, and in the fufion o filings of gold or filver, in the fame manner as borax is, It is even faid to increafe the malleability of metals, See Pots's Differtation on Glafi-gall. it A —— ES ——— Aen ost bismeita ibe RR tS bi tab an ka . a tT a ———— r TS A Eu ae pl V old is ftruck during a certain time by a hammer, or - - longer expofed ta great heat, i he GOLD hard, elaftic, and iff, and lefs Jutite, fo : be crackt and torn. The fame t ing. it . ber metals by percuffion and comprefion. tals in that a ility may be reftored to me ; Puétijhy a Tt, which 1s galled a fo DY old es to be more affected by percufiio | nem a Is, 2 he pay of gar of geld no much rs ¢ ten s can J . For 500 pounds ¢ £ o SH] Se eh in diameter made of gold, but not o wire of £5 : 1. : er con- Any O18 Is unalterable by air and by water. agp Ge be aft . and when its furface lofes its luftre, Ne fie is he adhefion of extraneous matters, a occafion : 3 : b deftru@ion of the metal. The action of fire does not by any f tl fed to fire it i ld, When expolec : fion any alteration upon gold, ired a vivid rednefs, en tal red, and when it has acquired Ite furfice has . ning coal, it foon melts. £ OF Je Fr ile ator 2 beryl, No vager of Pann rifes oe gold during its hes J contifued OF mone. : tion, howeve : > of wsighe by 2 pe “Kunckel kept gold ina glafs with ! till . d Boyle kept fome {1 poufe furnace during 8 kak ih the lofs of a fingle Hi becomes mor that it is apt happens to the ot os tion, Ht ; Sion 8 Gol i Lo pe its a jsentiie) fhe 2 hid of the firongell Bune Qe lint eithor by the pa a by fulphur, et they are pure, nor by fulp i kalis, i i Se bodies, neverthelefs, are nor. by a ’ : i mixture of of gold. The firft is a 2 fe Se rn ids, called by Fhe apa Tog t it di 1d, the king o H ch Pe prepa of fulphur with fixed alkali or of Sulphur, ia i A ver celled Sur of 8 of gold in aqua regia is ye ely, A very. {mall quantity of nitrous acid, or yen of h pepe mag wp with marine acid, gives this o eet pi f attacking gold. Allo a very imall quina; V3 a cid, or of any of the falts containing ih Sifolving 2 i cid renders this nitrous acid capable 0 Sloving 8 De antity of gold. But experience has ow ly iat i Ro Y imparted of four pars pi ig A by 308 one of fal ammoniac, Eifelvss perfectly third: Vou. 11. GOLD third part of its weight of gold, according to the ftrength of the acid. See Aqua Regia. To make this folution, the gold is to be reduced into . filings or thin plates, and put into a {mall matrafs. Upon this gold the aqua regia is to be poured, and the.matrafs is to be placed in a fand-bath moderately heated. As foon as the aqua regia is fufficiently heated, it attacks the gold with all the ufual phenomena which accompany folutions of me- tals in acids. But in this folution the res is only moderate. While the aqua regia diffolves the gold, it ac- quires a beautiful yellow color, which becomes more and mre intenfe, till it has a golden, or even an orange color. Ww the menftruum is entirel y faturated with gold, the folution is very clear and tranfparent. "The power which the nitrous and marine acids acquire by their union, of diffolving gold, which neither of them have feparately, is one of the moft remarkable falls in chemiftry, and favours much the opinion which admits the three earths or principles of Becker as the conftituent parts of metals, becaufe that fact is well explained by this do&rine. If ma- rine acid contains the mercurial principle, as nitrous acid contains the inflammable principle ; and if, on the other fide, both thefe principles conftitute metals, by their union with the earthy principle; we may eafily conceive that all thefe metallic matters, in which the union of thefe princi- ples is weak and imperfect, may be attacked indifcriminately by the nitrous and marine acids feparately : becaufe when any of thefe acids find in the metallic matter the principle which is analogous to it weakly combined, it may be capable of attacking that metallic matter by means of this analogous principle. But if thefe principles be ftrongly united to- ether, as many reafons concur to prove they are in gold, nce it is the moft perfe& and indefiru&ible of metals ; then we may eafily conceive that while thefe acids act on the gold -feparately, the mercurial principle may be defended from the action of the marine acid by the inflammable principle, and reciprocally the inflammable principle may be defended from the ation of the nitrous acid by the mercurial princi- ple; and that thus gold cannot be diffolved by either of thefe two acids feparately. But we may at the fame time eafily perceive, that if two acids united make a combined attack upon gold, that is, if the marine acid attacks the mercurial principle of the metal, while the nitrous acid attacks the inflammable principle, the action of this compound menftruum will be twice as {trong as that of any of the two acids feparately, and they may therefore / A GOLD ett af therefore perform the folution conjointly, which neither o ! fi ! ! . 3 - . ther Id SS cheation in its compofition fom She acids ; ow ia. ‘This folution is corrofive, as alfo all other > bipyes ed are. It gives aviolet color to the fingers, = 0 Ealtie ae] matters, for the fame reafon that finn; on 1 vet oe; is in nitrous acid tinge thefe matters b a] y 3F *h tion be evaporated and cooled, yellow snp sen : ftals like fmall topazes will be formed. But ft es 1 tion be carried too far, the acids with which t eg is Re nn be driven from ‘it by heat alone, and : e gals will be let in the ftate of a yellow pods, eid i be precipitated from 1ts folutio Wi vi eon which genenly Essie Vi Som i i volatile, acids; that is, by alkalis fixe : an Daina earths, and by fome other metals. A ipitate gold more eafily than fixed alkalis ; [ ie " S recipiteted from an aqua regia rade Winn: fal RoE by fixed alkali, byt is olen To 2 . ipitated by volatile alkali. Fixed alkali s De lly ad {peedily from aqua regia made with fal Wr De Ds but ‘in this cafe the volatile alkali in the Ra A falt, contained in this aqua regia, 1s gv en y difengaged by the fixed alkali, and contributes to the prec PALL thefe precipitates of gold, although yellow, haye oe a metallic brilliancy, becaufe they retain part of the di c d "ing and precipitating falts. In other refpects they, an i hing but gold f gold above-mentioned, are nothing ! Be wt en melted ition adden become en 1 ike tal before it was diffolved. ay ed by a volatile alkali from its folurion i aqua regia has an ftoniftung gropstys napa ni Dawe: oF : ETS En exploding with violence and terri ah se in degree. Itis accordingly called fi ns GF orranatvey. This property has not been ved i other metal. ) To of gold, that is, So, we aggregation : : ; ote, of which is entire, refifts the ation of iimple fo se hat it is abfolutely inca have feen, we muft not conclude t Tint i f thefe fimple folvents. De i) difcovered, that this metal, contrary, Mr. Margraaf has difc d, ihe ipitated by an alkali from its folution in aqua $ Dr op dered felis by any, even the vegetable acids. Be : soll s a fides, gold diffolved in qe ge is not precipitated, w a GOLD the proportions of the two acids of this com are changed, by adding to this folution any quantity of . nj. trous or of marine acids, Laftly, oold may be diflolved in alkalis by the procefs of the martial alkaline tinQure of Stahl ; that is, by pouring into a concentrated folution of fixed alkali in water, a fmall quantity of folution of gold in aqua regia in which the acids are not too much faturated, the gold will be quickly feized and diflolved by the alkali, All thefe experiments prove, that the juft intimate connection of the principles of the only caufes which render jt infoluble, by menftrua which eafily attack the other metals, but that its great denfity and ftrength of its aggregation contribute alfo much to this effet ; fince, when this aggregation is broken by a previous folution in aqua regia, it eafily yields to the ation of other folvents, oft metals are capable of feparating gold from aqua regia Y precipitation. The precipitate occafioned by adding tin, is the moft remarkable It has not the metallic fplendor, ther met have ; it is of a beautiful purple color when well made, pound menftruum Proportion and gold are not the or difficultly foluble his precipitate, called Caffius’s precipitate of gold, is ufed to give a crimfon color to vitrified ma TATE of GoLbp ( Cassius’s). Oily, thin, ethereal fubftances have great affinity with If a light, effentia] oil, and fill better if ether, be i i i the mix- o the oily matter, which will pon the aqua regia now deprived of its metal. Thisis one of the beft methods of making po- table gold. See Gorp (PorasL). Neither fulphur nor fixed alkali can a& feparately upon gold. But the liver of fulphur, which is compofed of thefe two fubftances, is alfo a great folvent of this meta], This folution can be wel] made onl by the dry way. To make it fucceed, gold-leaves are to rh mixed with iver of {ulphur, Put into a crucible together, and very quickly fufed. The gold will be attacked by the liver of fulphur, and wil] very of fulphur thus impregnated tters. See PRECIPI- ! gold, the tafte of which is very difagreeable, from the liver of fulphur, Stahl] as written 2 differtation concerning this method of difloly- ing gold, by which, he thinks, Mofes might have Said an GOLD , tioned in fcripture. ble the golden calf mentionec : iver of fulphar mmadork by he hii anges peo iced tartar by expofure to the air, g ino vi m it. ’ ml op sil = X foparess gold in liver of fulphur is fruciolatd “am acid, the fulphar and gold are precipitated together; eis cafe the precipitate is not ls a. rom the a . | t acquires 2 Pe th i: oi thus precipitated ogee He gol io : Br ore eafily faperible by fire, which co De 1 he metal pure. sn a with all metals; but thefe ae fio h od, excepting with filver and COpReny “ # gold mor Te re with mercury, in the satiation : gos nes I Matrix containing it, and for g ift Son by or a regulas of antimony, for its purifica lea thefe fubflances. metallic fubftance is always lefs d a os obfervation is applicable in uéti general to all a 5s A ily reed and render : 0 by end, oto conrg, much led nd Prcioied by a mixture of pe d Hop ore Rimes : ility of go . ; an . gi not be feparated from filver but by expofing us hae he ation of menftruums, which a and f{ul- EE the other of thefe two metals, that is, ac 0 - PX cher metals may be feared from god by crf oT : d by antimony, . Hon Jinn A ay Beane of all thefe iy J REFINING, CUPELLATION, PURIFIC ? of GoLp, and SMELTING of ORES. he properties of gold 7 that we have faid oncerning 4 edible, Ba b Sry tasam ’ oy oN Be But this does BLS JE ous anc le body, and abfolutely updiable, SOR Sh tra ', we have i5Rjon 10 blip ai bs ie . fu ficient heat 3 Oy : r inability to rai 3 a: pl to a fire infinitely Brahe op . al oa the fun, or even within the fun, it wou moderate Eo ea polon a he pet tae res 1 ho and ot would be reduced into vapors. 3! C3 and rendered po Some GOLD So ; ol Te hemifts pretend that they have been able ¢ : Sciences, that ays, in the Memoirs of the aleias haps, that having expofed gold to the focus of fagmy of hats os Wi; he faw this metal fmoke, and b {chirn- rosary nee! ling to the tradition preferved in esos a ‘and is one of ot nh not fufficiently aus pare (#) Ich require to be repeated with oe cals ea BY, that he changed gold into an irreduci | gd ne Se cnation, pith fufion, and Sy y St er o aacus H 11 d . 3 erbe- m 0 2 Tr 15 not very well A 2h Sxpert- Lat] Pe enough to repeat it > becqilie no chemilt tly, the true alchemifts d : offibili : $ do not mak Sugeno emily Sebo lt that this metal m ith procefles by which they” affirm, feparated ; its ful 1a be radically diffolved ; its Y anim, ’ § ur, ‘ . 2 princ 1 fel, 3 all be Dy ary i It, its tincture, and ite n > Pg rich Shs Sooty we find, that Lancelot and of the Eg eet concerning the Wiliom 4 Bos upon a por Eyer fay, that if gold leaves bo Ermey will of To A pa uring fourteen days and night Hiurgrad fomethin i changed into a black powder ik ihe gold whicl ne i Jolatile, of a fulphy en Sosins el illed with a grad : ell, an po ini, fome drops of % Co Leib 2 fellow 7s: lz periment is evid ] ’ . 1 ently v p it ml, ST, ts bios, thie, at during fo lon Tok SE almo irk pl heterogeneous matters Re Taaauigny, fenfible 1 > 1f 1t were only thofe which are conti 1xed with the the air. (x) ontinually floating in Borrichius (#) Homberg f: fuppofs g fays, that part of the gold raid i tgs Ue rel ight alfo Fin WR and therefore the ol : e purity of the gold which he employ But he from Some glafs produced in this experiment D oyed, and allayed NL 2 othr eh! with which the gold Als 3: proceed which a€tuall ) ¢ alhes of the charcoal which fi ve been y was th upported it ; Bris T that Eterm of fome perfons Tor a x) Junker alfo relates f el a long triturati ates from Borrichius and a bla E i ag of an amalgam of gol Jud Oden, that by {1 ack poweer was formed, which was convertible into green ys | $ glafs, GOLD ‘Borrichius fays alfo in the fame work, that a plate of 4 red-hot and extinguifhed in water many gold, being ma aftringent tafte to the water, which feems to times, gives an folution of gold by water. But was the gold, {hew a kind of and alfo the water, employed by Borrichius in this experi- ment, perfectly pure? We know with what difficulty gold can be obtained perfectly. pure, and that no Water but dif- tilled water is fit for chemical experiments. Becker, in his fecond Supplement to the Phyfica Subterra- nea, gives a procefs to render gold as foft as lead, and to en- creafe its fufibility. This procefs confifts in throwing melted gold a number of times into a liquor compofed of {pirit of - {al ammoniac and rectified fpirit of wine. I do not believe that this experiment has been repeated by any chemift. If it fucceeds, the foftnefs and fufibility which the gold ac- quires ma probably be ¢ fed by a fuperabundance of inflammable principle comn nicated to it by thefe two li- uors. : The author of a treatife ca..ed Alchymia Denudata affirms, that if half an ounce of gold be melted with two ounces of copper, and the copper be afterwards feparated from the old with eight times as much aqua fortis not depurated, >nd if this work be repeated nine times, the gold will receive fo lively a red colour, that it would {carcely be known to be old, and fo fixed as to {uftain all the ordinary trials with- out hurt or lofs. This experiment deferves to be repeated. We do not fee why the author dire@s the ufe of undepu- rated aqua fortis, or of fuch as probably contains fome marine acid. Such an aqua fortis feems, on the contrary, very unfavourable to the experiment; for as it is a little of the nature of aqua regia, it may diffolve fome of the gold. Roth advances in his Chemiftry, that gold may be dif- ed in Glauber’s manner, the folved in fpirit of nitre diftill vapors of which have been received and condenfed by highly ated with a faline mat- ter, and that by this method the gold may be deftroyed. Dr. Lewis obferves, that the green glafs probably proceeded from abraded parts of a glafs mortar, that the faline matter had pro- bably pre-exifted in the water, or was extratted from the glafs, an that the black powder was produced by the trituration of the mercury. ‘The fame author fays, that he has triturated an amal- gam of god during a week, without deftroying any part of the gold. i | Cs reQtified glafs, and that the water became impregn GOLD In this experiment know that ether h : therefore this fo as the ether is here affifted redified fpirit of wine. ‘mui be formed, and we fition to unite with gold fucceed better, - the nitrous acid s Nitrous ctlier as a {trong difpo- lution ought to by the action of gold probably does the ordinary tincture of 8: GoLp (PoragLe). gold made with Propofes as an ex- exceeding flowly, re-action of delj- is vapor feems by the impreflions j¢ but thefe qualities are believe that this vapor btle and active, makes upon our organs of fmellins . only apparent, and we cannot eafily 1s capable of diffolving gold, excepting the vitriolic acid be impure and |; ulphureous. I colleted q confiderable quantity of this vapor by faturating fixed alkal; with vitriolic-acid jn a tubulated glafs alembic, The ; when condenfed into a liquor, feemed to be nothin water. Its poignant fmel], therefore, feems to b i difengaged in al] thefe effer > and which by inter. pofing itfelf betwixt the parts of the water, gives this fpiri- tuous quality to the water, which Mr. Venel has fhewn to exift alfo in’the mineral, aerial, and fpirituous waters, See ATERs (MINERAL). ; Caflius, in his Treatife de tain very red cryftals of g purpofe he direéts gold le long continued heat, the phlegm of ordina of common falt. Auro; mentions 2 procefs to ob- old of a violet fmell, For this aves to be diffolved by help of a in a liquor compofed of a pound of . 'Y aqua fortis, and of four ounces Be- hed to a bafis without ys emits an odor fimilar to that of violets. Glauber,” in his Treatife 4 Lapide Animal; gives a pro- cefs for diffolving gold, by which alfo it is remarkably a]- tered. This procefs confiffs jn diffolving two or three ounces of hartthorn in a iftilli ut into this liquor, which js to o1 the gold in a glafs cucurbit, during ’ GOLD is di when the hich diftillation the gold is afin When 448 en off, at the bottom o : Ly vi biguor Xe compofed of all the ingredie Chis be : CO very quickly ne forge foes nd fn afs i ; he an rn Sais Ar is ed reriers white and UriiieTls por oh , If this experiment be es hihi or HHI ete hy the gold fhould sqgire hit whine pa pr efs, except we impute it to t hit HEI ar acid ; which acid, helng : nk Sl ¥ ro with the earth of the hart bie) maybe She Wr WA of a partial Seconppmngan | yh So A tion o prin by ce rh a believe to be one of he Go th F the matine acid, or, a arts 0 mar he of De pe Son | principle i ine acid. ; i pa J er dl Wi x iy oe a filled with say Beas Cn Seid ee ich urious and inte g na Wn _ ye yifore deferve to be ODER uy oe Soha he fame time almoft always ma) shuld, ar os and embarrafling CY A wi eamingticrs Thofe procefles whic neha Sefer J —" of this kind were Shores 53 vie es d which give the moft hopes of fu she practicable, oe who has yritten a Differtation, w i fe od vent from the academy at Rouen, songerh 8 aiedi ih Sous, gives a table of Mics gt ich pe cnemi ; De on | eins eg ps J ee ether, filver, iron, and regia, In incipal ufes of gold are well known. Rl et a, AW > ed into coin, and into various oy By Doi oh beauty, and undeftructible qua yr a) i i of gilding, much external esas, nea i en x is eh to many utenfils and toys. A Sse on WE raed from gold for enamel and precy 3p till Lo on have been of opinion, i ay PE bh edy fuperior to all others may % £2150; 4 he fey of procuring long life. an Lig aa than doubtful. See Goins orasLz). Witold, an explofive powder, more terri He o 3 * rr arecraet sg TN a y a — — GOLD than gun-powder, may be made. This minating gold. Sz Gorp (FuLminaTing). (y) GO FULMINATING). gold preeipitated from its folution in aqu fulminating, becaufe, when it is heate acquire a certain heat, it makes an explofion fimilar, and per- haps fuperior, to that of thunder, he method always ufed to confifts in diflolvin g this metal in 2 which the gol xed alkali. {y) For further partic ulars concerning gold, fee the articles SSAY of the VarLvug 3 Purirication of Gorp by ANTIMONY ; ParTIN G; and Ar- ng gold, its G ; Orgs of GoLp ; GiLpIN Every thing almo ft that is known concerni natural hiftory, its chemical properties, and its ufe i treated copioufly and accurately by Dr, work, intitled, Philofophical Commerce Ww ¢ fhall here make fome additions to the metallurgic hiftor of gold. 1. The color of gold is rendered paler by fufion wit borax ; which fubftance, or other flux, i of Arts, 2. The color of gold is heightened by an allay of copper, which alf; 0 encreafes its hardnefs, and when in {mall quantitity, 1 twelve, does not much diminith it lity. i Array. See alfo the methods of heightening the color of gild- ing at the article GiLping, 3. The malleability of gold is diminifhed by cooling it, when this meta] js fufed, too haftily, To prevent which, artifts heat the mould into which the gold is to be caft. 4. The malleability of gold is deftroyed by fumes of lead and of moft other metallic fubftances ; and may be recovered b fufion with nitre, Many authors fay that the malleability of gold is injured by the fumes of charcoal, but Dr, Lewis believes this to be a miftake. ¢, Gold may be melted with a low white heat, and when melted has a bright blueith green color. Dr. Lewis ob- ferves, that alth t of other me- ough its expanfion is lefs than tha tallic fubflances with fmal] degrees of heat, it neverthelefs ex- pands more than moft of the other metals when fufed ; and that this property, by t becomes folid which it fhrinks more when ; than moft other metals, renders it Jefs capable of receiving fharp and perfe figures, when caft into moulds, than filver, co per, lead, and tin, which do not fhrink fo much, and far lefs fo than iron or bifmuth, which expand in their paflage from a fluid to a folid ftate, 2 of powder is called ful. This preparation is aregia. It is called d or rubbed fo as to prepare fulminating gold, fufficient quantity of with {pirit of nitre d is to be afterwards A copious precipitate In arts, are Lewis, in’ his very ufefu] GOLD : lor is foon formed, fomewhat reddifh color 1s old. ef r Sols oo withed i dryed 1 Bee % of the T 18 P of fu mina oe ds. The 7 ys end wanderfol wie En But mo § this fulmination is not eafily in it. caufe of this fat may fuggeft hints to a ofed of ni- fhe fe d be diffolved : an i ik i and to which Irit, i id or co 1sitated . d of marine acl . . 1d be precipitate trous acid, an tac is added ; and if this gol On the no fal Ape pie does not te a trom by fixed all RN Litinates ftrongly, if It be Doe fats were contrary, 1t regia by a volatile alkali. fruums employed this ne Rue ill. One of the I shay call MEN ~ well known t d, is the liquor whi : lve gold, 1s the d of equal parts by them to diff . this folvent is a compound 1d is pom foe fray men Ht wil which vis gale of alum, > is then to be a ’ ; hi d; water 18 1d. By t is firft foils No {alts may act upon es n this Sigett 2 gold is found io e Ee the acids metho in. 1: id of the alu ia . triolic aci hus an aqua regi operation the i f the common falt, and t fecuentlV 10 of the nitre and ol | ammoniac, and confequently na : in which no fal am ller affirm, that is formed, nw Hoffman and Etmuller ai lution in volatile alkali, enters. fixed alkali from its folu : tated by a fixed : ipitate of gold does if gold be precipi itu, this precipitate of { Wi os i ri irminates ftrongly when the pre not fulm ’ tile alkali, ia in which cipiate is mad bY gold isdifolved in an mother by a fixed or : Sesapiiriw enters, its precipitate, whether by BE rls alieh, Told. is prepared, and all the b Thirdly, when fining go} find A its weight fenfls Ee: fully collected, we . that is, a fourt precipicate care f the gold employed; > old which by ot uy As obtained, than the go more . " kalis, be- was difiolyed. or vitriolic acid, or fixed alkalis, b t of its i has powder, deprive 1t 0 ing well ; fatto qeany of thefe experiments prove Saprlyy ht 1 rer to pre fulmiing pod, nus 2 tha the . : ft be formed in Ifo that this meniacal falt mut be ht of the gold thews 2 Taé the mtn of ie i 1a oe Ed dug cation; and incorporates with it. Laftly, GOLD Lally, The methods, by which the ful of this precipitate may be deftroyed, are alf; compofing the nitrous ammoniacal fale. phur, or vitriolic acid, feparates its nitrou itriolic ammoniacal falt, b and the fixed alkali dife itrous acid. All thefe fa&s feem to prove, alt formed during the precipitation, and intimately unites with the metal, ammoniacal falt is known to when heated to 2 ce be fufceptible of which property le matter which i on of nitrous am when compared with tha ofive bodies are known t is occafioned b quantity of inflammab tains. This detonati very fmall, the gold as the meta]. If the explofion of the fulmina the detonation of the nitrous a tains, as we have reafon to be effect of the inflamm chiefly confifts the de ¢/ Nirre. Mr. Beaumé has a ation of the nitrous ful tonation of nitre. Se. s fulphur which occafions the fulminas d during the precipitation by the union nitrous acid ; tion of gold, is forme of phlogifton with 3 that this nitrous {ulphur - exifts mixed with the gold, and ready formed before its fy) mination ; and confequently that the nitrous ammoniacal falt does not contribute to the production of this effec. The chief proof which he brings to fupport this opinion, is, that if fixed alkali be poured upon fulminating gold, no mell of volatile alkali arifes. Beaumé further affirms, that fulminating gold may be boiled in any quantity of wa-. ter, provided that water be pure, that is, diftilled,” without ofs of its fulminating quality ; which experiment feems to ew, that the fulminating quality is not occafioned by any - faline fubftance foluble in water, as the nitrous ammoniacal - falt, but rather by fome fubftance infoluble jn water, as the nitrous fulphur probably is, from its analogy to vitriolic ful- phur. This is certainly an ingenious thought, and we with that inating property 0 capable of de- The acid of fu]- s acid, and forms y umiting with its volatile alkali; enages its volatile alkali, and forms ordinary nitre with its n : that the fulminating pro- perty of the gold is occafioned by the nitrous ammoniacal and which very ftrong] Further, this nitrous detonation rtain degree, and without addition of ap combuftible matter, ts volatile alkali con. moniacal falt ig indeed t of fulminating gold. o produce explofions fo ting gold only proceeds from mmoniacal {alt which it con lieve, it muft certainly be the phur, in which DetonaTION particular opinion on this fubje. He thinks that the nitrou GOLD . ’ d explain it , fecute, prove, an aumé would pro roUS). Po n3 as See Sues ne nF gold, ho fully, the caufe o it is one of the But whassvey Ye explofion occafioned hii pi Tt is not ne- are certain tna hich are known in chemi hed by an ignited moft violent oy inating gold fhould be tou becomes red, to ceflpry Spies {hould be heated till it Ea matter, or ti = heat which ; betwixt that of boiling wet ond the lone] dnd termite, Is of an obfcure = ol fufficient to make it ES ¥yary confiderehie, 15 WM in open or im - even a friction not’ Fe is produced either in opel old fulmins § "Thefe circumanees rede A, Eo clofe veliels, 3 1 chemifts, from no ile they were ye yan gerons : oe hurt or killed, oe wing ing its efieC f) devi it. I was witne rv. Had ying ked in a laboratory, pounding an ne man, who worke lafs bottle, and pecidenti A JOUR » ating powder into a glais k of the put 2 dram of fulminating er furface of the nec e the inn 4. When he had neglected ® fo hi of the powder adhered. ftop= ing the glafs {top= bottle, to which fe this bottle, the turning t h fioned fuch a endeavoured to clofe t Git more clofely, occa ke it nt m art of the Finan, has oe gongs rocco ke pe Ue riction, B this cxploiio) £ e woulite oyder, explode, BY his face and hands wer od thrown fome Hp x VR and his CREA by the fragme: iolence of this exploiion, th : he violen . dé. Pro- SE gold did certainly nok Sepls , wes grain ola ery little of it was oes, tor in its une 2 WY: nd {cattered about in the labo ’ afterwar xploded ftate. kind is fo terrible, and at the fame om fortune of this kind is ofe who are not fuffi- : A To difficult to be prevented by ale A fins 1 i in chemiitry, that 1 thoug this accident ough be pia fudden and vigleatd Rh ; * + - € - The gaily oe i i be aflured, by Sera ing mation. Of: oe gold under a glafs oS ! a be efor "3 Quenuly of from the explofion. > ih Sic fate, to the 18 a3 in its pro \ adhere, 1n its p wards obferved to ad > inner furface of this bell. (2) GOLD tat] der feems to be more f fulminating pow : 1 quantity ow amg bus es forcible than hata 4 cl 0022 fudden kl ¥ The quicknefs of the a gold of gunpowder, OLB ftate, feems to be ac= : 5 vr of cold, inits natural nk sacks wh vi. GOLD “This inadkivity of £06, 7 for Boy con radically (P OTABLE). Alchemifts have always be knowledged bY Je remedies desire to an intelligent many di he rolongaion acy Lo the or Give tBu this prtnfon o 3 40 a ns ‘ ei 3 - . ar confequenly laboured much s a this Ohyfician oi I oe, the Ag that fuch 2 — ay i i J oT are foe EI et this mee) A a > alt > uppo 1 w pable of Curing 3]] evils. : {olution oa goa wnnccellary. API) we find that the moft intel] tues reparations given fo Po the gold which Deh ¥ phyficians, amine er contains i gE fly extralted, and reduced to of its great i a part 0 tain may be €2 do actually con souflv diffolved. Bo natural ftate. 1d potable, it muft be PY the acids, To render gO e in aqua regia, or even thod gold and the This may be SE ; but by os, pe is fo well known, with proper ma rendered corrofive. that their folutions other a of potable Ed the very thin =n that the prepare acid. . Dut 28 all It to unite wi are made a i a ftrong diivention find it much volatile oily fu lly unite with it wi oh tinGures of gold, and do rea i may be nade o A rations do | divided, Wy hey, potable gold ee they contain, s, : r Kin ] the go ‘ t gold is inferred from the loudnefs of jts noife, which is much By any virtue fo inflammable fubtile matter, greater than that of unpowder ; and from its perforating or im- no have at leaft that o prefling a metalline Plate, upon which jt js laid unconfined, and | they is exploded ; which effet 1s not produced by gunpowder; the caufe of which feems to b ESSENTIAL) h is the vehicle of the gold. See O1Ls ( Ti whic 1S €, that the force of the explofion of iw gunpowder is applied ‘fo flowly and gradually, i from the pa : the vitriolic a on! Cie ntial oils, ethereal liquors fuch as Fh e that it may be id Subtle e rt of the plate whic other parts of the plate, and thus by the vis inertie of t : ith a folution thers, being mixed and agitated wit and other e 2 he whole plate ; plofion of fulminating gold plied to the contiguous pa g or impreffing tha is : a riving this aqu regia, have a property of dep g hi p in aqua , i of gold in whereas in the ex- ue » the whole force : fur- Cr, 0 as to carry it to the fu ; ich it feizes, foastocC aug. fori. regia of its gold, a je gfjoats -upon hh principles. is fo fuddenly ap- a fate of the liquor, SFE old are upon Faculty of Me- rt of the plate, that it is capable of Be | Many receipts ror Pe Difpenfatory of the itating fixteen t part before it can be communicated 3 One of thefe 1s he onfifts in mixing and ag of ‘sold dil- to the ref of the plate. Now, though the force applied during dicine in Paris. ltc f rofemary with one part BO regia the inftant of the explofion of fulminating gold, be greater than arts of effential oil 9 feparating afterwards thi S24 ntains “the force of exploding gunpowder during that inftant, yet the P lved in aqua regia, 1n icp the effential oil which co ia fum of the forces of exploding gunpowder, in the feveral in- o deprived of gold feo tial oil in five times its we Pe fants of its explofion, is probably much greater than the whole Hus d in diffolving this € ai is preparation is the fame force of fulminating gold, becaufe a quantity of aurum fulmi. it Cedtificd {pirit of wyne. 11h Pf Lemery’s Chemi n: hans fhut up in 3 firong hollow iron ball, and heated in the fire, of 18 y: ribed in the laft edition Mademoifelle Grimaldi. did not feem to explode ; while gunpowder treated in the fame that defc name of potable gold o operty of taking gold manner burft the ball, This experiment is related in Dr. Bivch's under the ial oils have the fame prop Hiffory of the Royal Society, vol, I. As all eflential ol Dr. Black attributes the encreafe of wei Plotive Property of fulminat ith any of may be made wi ght, and alo the ex. from the aqua inch i EN ing gold, to adhering fixable air, See thefe, as well as wi 5 efay on quickiime, amon ght the E lifhed at Edinburgh, Jays phyfical and literary, pub- vol, 1I, Al This gc the fame g perceived ld under the name of imagined that this Preparation thefe drops are mifcible with water in any Proportion, a quality which does not belong to pure ether, this fme]] of ether probably Proceeds from 2 fmall quantit ] her formed by the mixture of the nitrous acid of the folution of gold with fpirit of wine, both ‘which are certainly ingredients in this preparation, II thefe tin@ures of gold are nothing byt gold in its na- tural flate, exceedingly divided, an, pended in an oj] i €Y are not therefore, Properly fj peaking, tinGures, n they be called potable gold in any other fenfe Wms in a fluid, and js divided into fo apt to depofite they contain Gold is de- ether, in its me- 2 as gold may be diffolyed and redy liver of fulphur as may alfo be made by that folye feen any potable nt. Neverthele gold made in tha the infupportable fime]) and tafte o GR AT N. A grain is the fmajle weight ufed in the or- inary operations of chemiftry, Tt js nearly equal to the weight of a grain of corn, from ich it has received its ‘hame. A orainj a fcuple, 1, part of a (a) vegetables are fp § are diftinguifhed jp chemiftry, nt fubflances which are obtained . I¢M contain at the fame time a con- ced into a liquor, by aqua regia, a potable gold fs, we have not called, (2) The weights mentioned. in the text are French, A grain is J:th part of an Englith troy penny weight, or s3oth part of 2 troy ounce, See the article Weignrs, ° fiderable RaSh. ga A a a — lin GRANULATION il, which may be fepa- . ilage and oil, wh fion in water, {iderable quantity of ry Ri former a trituration rately extrated fro reflion, or both te are therefore and the latter Dy of an emulfion kind are almonds, with Wate, in ain or feeds. Of t ther grains are called called emulfive Bo oft all fruits. The n erabundant oil like and the feeds of a ufe they contain Bo, FLV; a dry fubftance farinaceous, 2 5 Re entirely Compo He d meal, from which the former, : u into a fine powder, ca cilaginous, nutri- eafily seduce 10 a large quagnty % how fufceptible oPshe ter can €x| nd which 1 rains of a tive, faccharine tation, Of this kind Eo hich are fpiritucus pH plants, the fru ramineous and . rains. d by the co- a coverings igh Lo is a’ ftone fore 3 different G » aT fones of different colours, ) hefionof fma ; compofed of {ma natures. . ftitutes it a ftone ted granite. The A oe ; and hence 1t 1s Vi {pars, particles, called g e formed by particles As quartz and Mok fone re fr i fand, and mi ftrike inate in granites, thefe {tones fand giresaly predom 2 ftones. ft the hard ! claffed among &. Granites fire with free ag » differ much in this i beautiful Neverthelefs, gra affes. Some of them ites are found are found in lar Be hed Many beautiful gran brought from when cut and poli moft valuable granites are b in Brittany. . ion Povpt. (b). I.ATION. Granulation is en o GRANNY f bftances are reduced into facilitate their which Wh the ufe of which 1s, to i . rospdilh put with other fubltaness, confifts in pouring 2 led mal lowly inta a vellel fled wi Broom. Lead is mea time, x0. be agitated with 2 Brag in the mea ’ ie hond rance, as they bo : rious in their appea ticles. Thefe (2) Gagne RS oraoes of thelr com Drs 2 rhomboidal in fhe otors Phe P £ mond ; of Leper | dentally sized particles ot mica, with which alfo Bre bafaltes, garnets, ae quartz, an her ftones, as of fteatite * the higheft wy articles of other ocky fummits of t orphyry, whic metallic Wi oP eR ey fone, tof porn only in con- enerally confi d ftone, and different fro g great deal of the je fos aot qiarea; feltfpar, and mica, fo Ec olred tone called ES isbiiataliic: heii Mr w GRAVITY alfo granulated by pouring it when internal furface of which is-to be rubbed with powdered chalk, and by thaking ftrongly the box, till the lead has be- come folid. "What paffes in thefe o come perations may be eafily imagined. Metals are granulated, becaufe their ductility renders them ipcapable of being pounded, and becaufe filing Is long, tedious, and might render the metal impure by a mixture of the iron of the file, '(¢) GRAVITY Gravity is the property of bodies, by which they endeavour to approach each other. Thus, for example, we know that a bod earth can- not be raifed but b perior to what is called 1ts weight ; and that this body, thus raifed, returns preci- pitately to the earth, when it is no longer fupported. Men In general have always obferved this phenomenon without attending to it. But philofophers have always admired it, (¢) The granulation of metals by agitation in a box, is thus ex. + Plained by Cramer. The metals capable of this kind of granula- tion, aslead, tin, and brafs, are very brittle, when they are fo hot as to be almoft fufed. The chalk with which the infide of the box is rubbed, encreafes the refiftance to the motion of the agitated When the melted the vefiel, it no melted into a box, the metal, and preferves the box from being burnt. metal is fhaken and dafhed againft the fides of fooner becomes folid, and confequently exceedingly brittle, than it is thivered into a fine duff. Thofe metals which are rendered more tenacious by being heated almoft to fufion, as gold and filver, muft evidently be incapable of this kind of granulation. The other method of granulation may be performed by pouring nterpofed betwixt it and the water, al is divided into {lender ftreams which are further broken by the circular motion of the water. See a de. feription of an apparatus for granulating copper for the purpofe of making brafs, in a note to the article Brass. Melted metals may allo be granulated by being poured from a certain height into a veflel of water; or of other fluids capable of fixing by their cold. nefs the drops as foon as they fall, and thereby preventing them from again running together into large maffes, ~ This granulation may be thus explained, The feveral parts of a fluid poured out of a vellel, begin their falls at fucceffive inftants of time. The velo. city acquired by each of thefe parts from the accelerating power of gravity, is proportionable to the time from the beginning of its fall. ‘This acceleration of velocity produces a continual increafe of theinterval or fpace betwixt any (wo parts of a fluid, which have begun to fallat different times. Hence the feveral parts of a falling fluid tend to feparate from each other, or to form diftin® mafles op drops: and they accordingly do feparate, when this tendency is fironger than the force of cohefion by which they are held together, A and RAVITY (cover its caufe, but without fuc- and have endeavoured to di ¢ do not yet know all ; ; for w :-h is not furprifing; f not yet cer- Hes i attending ge Aptis i. The the rticles of ma : laft age. We tain, that all the past not difcovered till the la te gravity of he et to reafon upon this ay much will not therefore attempt 0 Fo 0 De eavity of the ject. But orien: and as the particu obo] the pri- all chemica 2 of different fubftances 1s pro Re y other, mary caufe * ‘nto fome detail upon this ae tO TANHErS, we muit Shiet of a body may be confidered In t be compared The gravisy dv. confidered as heavy, OO of matter. Firft, every : = Tels quantities of the fame the quantity of but to gre? 2 e may obferve that the ee f its gravity. In this ey op paly is, the greater a He oo es mafles or matter o : ies is directly as . Hence she gvity of Be i of bodies confidered in quantities : ravity, that is, their weight, this view 1s Hel Sn Gene > any gortain quasi or the olin nrg ee Judge, hat the qugniities ofa To Of stir. er diffimilar, are equal, if ‘ ey pect 2s fubftances, homey vit. The weight, there or A Sel ig Ss are the fame thing. f oh of quantity of a ine the weights and quantities ofa Po agreed to etens certain effets of gravity, an a DE ore or lefs confiderable pi MO Giffofent nameyto DN &c. fo that two quantities ol | on drams, ounces, pounds, he fame effect of gravity, th: fubftances, which produce the A ounce, Sc. are jutly . 4 r of a dfam, of an Satu prand 00s in ual. In this fenfe we fay, This abfo- oF lad is no esi han a pound of coc, TBE ue gravity, weights or QE LC vi sale meafured by a on its center of gravity, whic Tghiee » Dine i Y middle of its length. Two UF the lever exadly in t . vi ended at the two extremities of t x vas Te a el or of the fh woh, w 0 ry : e . Oe maintains ih a Joriassie 2 a tae. isi u RR : ha giehel: tines It 3 ch hd ro 3 : ; > which oug » J i i racy. miftry which require accu y GRAVITY In the fecond place, we may confider a body as heavy, re- latively not only to its mafs or quantity of matter, but alfo to the {pace it occupies, that is, to its bulk. A great dif- ference is found in this refpect, among natural bodies. This difference proceeds from the greater or lefs number or fize of empty {paces, called pores, which are in every body. Bodies which are not very porous, muift evidently contain, under the fame bulk, a greater quantity of matter than thofe which are more porous ; and confequently a body of a certain fize, but not very porous, muft have a greater abfolute gravity than another body of the fame fize, but more porous. As thefe differences depend on the particular fpecies of each body, gravity eftimated in this manner is called Specific gravity. It may alfo be called relative, becaufe we judge of it by com- paring bodies with one another. This gravity is the fame thing as the denfity of bodies. . The fpecific gravity or den- fity therefore of bodies, confifts in the relation betwixt their abfolute gravity or weight and their bulk: and the fpecific gravity of any body is fo much greater as its abfolute gravit 1s more confiderable, and as its bulk is lefs ; or, in the lan- guage of geometricians, it is in a direc ratio of the mafs, and in an inverfe ratio of the fize. Hence if two bodies be equal in fize, they will be to each other as their real weights or maffcs : and if they are equal in weight or mafs, their fpecific gravities will be reciprocally as their fizes ; that is, the fpecific gravity of the lefs bulky body will fo exceed that of the more bulky body, as the bulk of ‘this latter body ex- ceeds that of the former. As the denfity of bodies is one of their internal and effen- tial qualities, the knowledge of which contributes much to diftinguith them, and to throw light upon their nature, phi- lofophical chemifts have always applied themfelves to deter. mine this matter. By this method the purity of metals, and of feveral other fubftances, the degree of ‘concentration of acids, of liquid alkalis, of fpirits, and of other folvents, may be afcertained ; and thus important difcoveries may be made. For inftance, they have difcovered, that by allaying metals and femi~metals, metallic maffes are formed, the fpe- cific gravity of which feldom correfponds with what it ought to be, if thefe metals were not condenfed of expanded by the allay. Thefe experiments, however, are but yet begun; and we may prefume, that in profecuting them, the fame phe- nomena will be obferved, and perhaps ftill more varied in the folutions and combinations of all other folid and liquid bodies, \ ¢ | GRAVIT may find by this means explanations of nd that we ing falls : interefting facts. tly deter- many obfcure A bodies may be dy Y ative, The fpecific X einods As this gravity fubftan ce fimple mined ye] by coupon ales phi be made as and can be € which at lealt mig the weight of and invariable, or wi dicioufly chofen, to mpared. hic E> Bede of A other fublisaass and Pfitied Rr. which the 2 + ns are found in pure ly a determinate All thefe conditions 1% ery REO aser Tn o pid! Accordingly Dy ftance, of pure oni, the quantity, precifely the {pace i er A fluid to the fpe- and marking . ity of an . For this . » {pecific gravity determined. Forti relation of the fpe may be eafily de : he phial : 1 f this water may b> id be put intothep > cific gravity 0 ) ntity of this fluic Sh h the water purpofe, Ie ly occupy the a or dh that it fhalle curately weighed. AS their fpecific did, and let it Pe ac mpared are equal, He 3» ir abfolute two fe or in Pv a in Fe gravities 2 he liquor compare wit B weights, if the liq ater 3 pare 1 to that of water; : will be equa han an x ecific ravity wil or lefs than and if, oy ry i my och more or lefs and if, O . ity wi € . r lefs . ecific gravl Y ' eich more oO unis a iy BS eorbing ast i ue 8 liquor equal than that ce. If, for example, this ounces, its fpecific then ; hes of water, weighs we on the contrary, to that o hat of water; if, Of ity will A . uble that . gravity wi gravity will Be only half an ounce, its fpecific gravity The liquor wet ater. 3 he Jy half as much as that of w icnt, and the beft which be on y thod is very juit, convenic fe ravity of liquid This ated to determine tne {pecinc g y be all re- can be em ility wi hich they ma {ubftances, from the facility i management and addrefs t 3 v duced to an equal balk, Be the fame alley poi) por cquifite to give preci afirm Bre requ do ois precifely we may oR be ufed, to deter- a ble : therefore another eo dies We have oblerv- po ific gravities of iolid bOGIES: 1 bulk are to mine the fpeciic gravIEEE © of bodies of equa n e {pecific gravitie a iohts, and upo ed, that the pe ta {olute gravities or wceig ? ded : their abfolute g lained is founded; each other as d we have explal bodies ; inciple the method we f f two or more bodie this principle weizhts oI tw . . fe the mafles of woe r in the inve bie op oie gravities are Ee or ny a bulks. ¥rom this focory) of of folid bodies. 0 : i avitie : a eafily determine the fpecific gr in reducing the The method ufed for this purpofe confifts 8 dics 3 bodies, 2 GRAVITY bodies to be compared to the fame real weight, and then in comparing their bulks to each othe thing) the effects of thefe bulks u quantities of water, as we fhall fee. When, therefore, the fpecific gravity of two folid bodies is to be determined, an equal quantity, an ounce, for ex- ample, of each of them is to be weighed very accurately in y method, whatever be the difference of their bulks. Each of thefe bodies is afterwards to be weighed in pure water, by the hydroflatical balance, and the difference between their real weights, and their weights when they are immerfed in water, that is, the lofs of weight which each of them fuftains by this immerfion, is to be obferved. Thefe lofles of weight are then to be com pared ; and the body which has loft the leaf} exceeds the other in fpecific gravity, in the fame proportion that the lofs of weight of the latter exceeds that of the former, To underftand well what happens in this experiment, we muft remark, that if 2 folid body be immerfed in water, and if it be left in the water unfupported, and without giving it any impulfe, the bulk of this body will occupy the room of a quantity of water exactly equal in bulk to that of the im- merfed body ; and if the fpecific gravity of this body be equal to that of the water, it will remain motionlefs in the fame Place where it was left, becaufe its real weight being the fame as that of an equal bulk of water, it remains {upended in the water, like an equal quantity of water, that is, coun- terpoifed by the gravity of all the furrounding parts, and confequently at ret, and in an equilibrium. ~ But if the fpecific gravity of this body be different from that of water, then no equilibrium can exift. If its weight be greater than that of the water, it muft neceflarily defcend to the bottom of the veflel ; and if it be lefs, it muft rife to the furface of the water : and the force with which that body will rife or de- fcend, will be proportionable to the difference betwixt its _ gravity and that of water. If, for example, when it oc- cupies the place of an ounce of water, it really weighs two ounces, it will fall to the bottom of the veflel, but with a force only proportionate to the excefs of its weight above the weight of water; for as it cannot fall without continually difplacing the bulk of an ounce of water’, therefore one ounce of its weight will be employed in balancing or coun- terpoifing an equal weight of water, and the body will de- {cend by the effect of the weight of or with half its real weight, pon the fame or equal the remaining ounce, Hence, if that body be fuf- pended ry or (which is the fame . : : it may be counter-: balance, e 5 0 cfs py of ts in the fcale falpendel | y for i in air, and conieq : m O in air. v in water, than in al be one half lefs heavy in annals weight will appear to ftablifhed ; as a bodyof 2 as its bulk is lefs, This being f (s of this weight 10 water: relation, We may lofi 0 a things are 11 the i, when we weigh r; ¢ and as theie tV te one for the othe ’ 2 judge oi the Hirefore li of equal weight, we may in water two eciate their f their bulks, and confequently may appr relation of the {pecific gr dimi- ? aring the ining and compa ‘1 water. ioe by determining eiched in water nie which they fuftain wher ation of their nution of yoz ore eafy and exaét thanam oe m his 1s muc The Thus, for examp pended at on poifed by an the other ar dies le. if we weigh in water ts i 8 I ¥ ar 1 and if the one lofes a oni PR o equal weg and the other lofes only his ter e bulk of t weight in the ae from thence, that th e may € part, W mer, and con- 2 one half lefs than that o the forirs he fpecific latter body I fpecific gravity 15 double; the inverfe ratio 0 fequently Rr of equal weights are in gravities 0 Their bulks. See w ar . itv of bodies, bu water, itn (aid concerning the gravity a From what ie nd pro- : ‘nino their nature a . n examining oe 1s attended tO 3 eive, that 1n dies is attended We Tay Fe fpecific gravity only Oe weights ufed to erties, avity or ra 2 of ] which, abfolute gr . d conventional, and that the . bitrary and ew he mine it, are things ar bolute gravity, when they fetes determine well the 2 te. But we muft ob- Hon Tos are determinate and wi a great inconvenience themie : ike meafures, ha Cn d diffe- johts, like ced arbitrarily an ferve, that weigh They are fixe ound . ine uniform. at an ounce, or a p ’ in not being tries ; fo that a “a other in different coun ’ try as 1t 1s in an ’ rently in di : in one country . om- r the fame . d errors 1n C 2 hich lr ily introduces Coan, 83 be fixed but by an whic Carts. As weights ca {ed to ; c arts. AS CN to be ule merce adn age bulk of the bodies npunded r be firft ren- eps mes ts the meafures eR a “; be expected. fix theic WEIZRTs, ions, which 1° ; fa form in all nations, abl ‘The length o dered uniform - is very pofiib C. 5 ator ing, however, Is “rv {econd under the equator, ‘The thing, NC H very iecon é rates every hich all others may lum, which vi {ure to which a eS pendu d inv; able meatur i erfal if : invari be univ ’ 1s a finsgne would be very proper 10 b¢ execution of be re a ld agree to it. This Pl fo commerce, arts, nations Wo reainly be very favourable opofed Dy M. yeh ely mankind, was prop de IL: fciences, an Da bfe a GRAVITY > in a memoir which he read at the Acades de la Condamine my of Sciences. To compleat this article, we muft examine what effects are produced by the gravity of bodies in their combinations and decompofitions, that is, in al] chemical operations. It isundoubtedly the moft important and decifive object for the general theory of chemiftry, but it is not within our pro- vince, as it eannot be well treated but by help of mathematics, In this point thefe two fciences; which appear fo remote from each other, meet. A man fufficiently intelligent and able in both, might, by treating this matter accurately, throw much light upon it, and lay the foundation for a new phyficomathe- matical fcience ; or rather, might render the application of algebra and geometry to natural philofophy much more general. Several perfons, and lately Mr. Sage, in a Differ- tation, which gained the prize of the Academy of Rouen, concerning the Caufe of Chemical Affinities, have advanced fome fteps in this path; but great difficulties will probably occur. Perhaps chemiftry is not yet fufficiently advanced to be fubjected to calculation 3 perhaps even it will never be fo far advanced ; and although men of genius have, fince the refto- ration of the fciences, carricd mathematics to a greater per- fection than it was believed could have been attained, the problems which chemical phenomena offered to geometri- clans may be fo complicated, as to be above the reach of human underftanding. However that may be, in the application has been made of the to the fyftem of the world, and t the celeftial phenomena. If this heavenly bodies, fo happily obferved, and fo well calculated, be an effential property of matter in general, fons induce us to believe, its effets can very large bodies feparated from each oth tances, but muft neceflarily a&t betwixt the {mall particles of matter at very {mall diftances from each other, and confe- quently in chemical combinations and folutions. Although we do not precifely know the bulks, the maffes, the forms, nor the diftances of the integrant and conftituent parts of bodies, we fee them aét upon each other, unite or feparate, adhere more or lefs ftrongly, or refift all union ; and we muft believe that thefe effects are produced by the fame power ; fuch, for example, as the reci procal gravitation of thefe fmall particles to each other; which is varioufly modified, accord ing to their fize, their denfity, their figure, their extent, the intimacy fe latter ages a moft happy theory of univerfal gravit o explain very fatisfactorily univerial gravitation of the as many rea- not be confined to er by immenfe dif- vVITY Gs R the greater Of lefs diftance of shtimacy of their contact, 1 : h. inftruments, al ren] r approac ther in ns of heavenly thei telefcopes, and oe iftance, ary ta Hive indeed He applying caleglation boil 0 of thefe great bodies ; an rceived the gr f that gravita- difcoveries, they have py determined me on fetunl tofhew the bodies, oe he crofcope has ee and. when ae tion: but the entary parts © 0 : theor of univeria He endeavoured to apply the (heat) 7 cong f terreftria inverfe vitation to the phere ° a dhe. rule of the in ra Eon ‘di . : iftance was that this gravitate of the diftance, Pho SE does ratio of the i Jaw of gravitation in id whether this very fmall. Th . been yet well Setspie of fads, or be- not appear to ha ant of 2 fufficient fu: Sot ft geometricians proceeds i examined by the 2 caufe it ha , . int ine this point, ifely determine Gly. and cannot prec t indirectly, But although we te ) ble to approxima h the more would it not be defira » This appears fo gw need not by making fuppofitions mes, the fpaces paity . i i be ities, the t1 - 1i.n] revolutions to eafy, as the i hor Sy parts of bo- be obferved gi the motions of the ele and fubjected to the determined h certainly very regular, inutely, and only by dies, althoug cannot be perceived mil tants. They are fame fixed he are made indivifible 73 ording to the cir= their effects. but Serpetually vasidng, a therefore con- not conftant, hich determine them. ho in a vague manners Cele objects but in general, or 1athet ih SIRE LL ch fider thefe objec I afk thofe who are Cap atoms of matter are But, howe er ofing that the {i ueftions, if, fuppoling y bodies : » which the heavenly € Qed by the fae powss by wh onfider their tendency affe mn her ; may ¥ attend to gravitate to each other; [BAY f no effect, whenwe 2: Ym © arth as 0 tary parcicles, She Comte? o he fmallnefs of thefe elementary p . the almoft in 5 h . ey may approac : e at which th y «Tn afe to . ce oeely {mall diftance : oht in this caie ri the infinitely Too of their gra ey are, as It Were, each other ! d to each other. : t liberty to them ten {t ; or, being a be, to make d from the reit; 9% on each 3 {eparated iro re-act up . {mall a tendency, i J counterpoife ield to their rec difturbed by Tbe In the ithout being. ditt od uilibrium. other, witho a whole univerfe in an J hefe molecules of which kesps as the diftance betwiX { nd ace, , ot one at a bodies > infinitely {mall, or 1 aftronomers have ll, may not conte dis oa HAR aa torn ss a GRAVITY be fubftituted for it } And in this cafe, would not the force with which thefe molecules tend to ea] together, be in ac £ SpE £ the diffolved body be no 1 other, or adhere Tl its activity: the parts © , : t i denfities and con- tacts? Hence jt ® & with cient conta If, on the Sof Wn cannot have i i all the tendency of iently denie to fatisfy enti fufficien folvent to the io them to have the m mediate cont : {atura- / A imperfect ‘ ihe parts of (uch 2 combination 2 i will {till pan oft extenfive and jm- is Jem hE bodies. This may be act, would be the hardeft of al] boine or h to at up thofe whofe aggregation would be the rmeft; fuch, for ex. 3 ample, as we conceive that of vitrifiab that, o bina- d other com : t {alts, an CE. force Fa neutral deliquefcen DELIQUESENCE n le ftones to be : and ferved 1 n the contr ary, bodies whofe primary integrant mole- cules fhould have the and aid, that See SALTS, has been {a1 ’ 6 is nature. ; om what . ts O tions of a we may Per jee and confi a J I n {uperto : leat denfity, and fuch 4 figure that Four hich makes the 1 h much {up li- whic althoug : wever 11 they could not have but the {malleft pofiible contalt, would the to each other, ter of the earth, 18 hows even be the leaft hard of a] bodies, or rather would be fluid ; fuch bo towards the ite in its fel, 3 manner pure fire appears to be, and the other {ubftances eflentially Br . that it muft be Sivcamitances. Ia the which yields . . 1 / Auld, I Bg fon eo oF no effect in sera integrant parts of Ee on fidered as any n the third place, if we ofe primary dherence 0 = ht not to d to 3 a ou ; ces them ten integrant molecules have avery greatdenfity, but can have on] as the 2&ion of a futventy Ea which makes th they can- very fmall contadts ; whether that may depend on thejr figure, to the 1 comparifon of t os that after the fitution ¢ Li of or the interpofition of fome other fubftance with the parts of rn of this folvents, together, but only Ee elie 7 a : i t unit > . we which they can alfo have but {mall contacts ; then we may Jot any longer be he fame manner, 1 by of a compound evidently perceive, that the force with which this folvent ; font unites the principles 8 J when, on : . Fd Cc 3 e > : tend to unite together w ’ y be) that the force whi ht to become ine ( principles is en- will be in a continual nifus of effort, and dv to each other oug f the parts of thele p he other fide, lowed to fay it, in a ftate bor the ae ly and when, on the parts of Lh 0 1 1 fhall have withi rely exhaufted vy o pe another Boy aot may to this of the principles To that which they i ich thoie © . ‘velv {fuperio “ inthis’ whish 4 an union, A of the gon e dif- col f theother evi a . ts oO t ‘ nd mu d remaining tendency to unite, or their EN with P Srinciples of the Son form a new compoun . >! ; ui, cafe, the rinciples uch appear to be mineral acids, and in general al] chemical ls one of thefe p P folvents; the a&ion of which cannot be conceived, unlefs uk we fuppofe that the force with f x ; d the molecules 0 applied to 16, an uft exercife : to | with the new Leis, now difengaged, m which their Integrant parts a the other principies, tend to unite with the particles of the bodies which they dif- @ -folve, is much greater than the force with whi are kept united. . agoregates pon each other, and A yield i their tendency Upo have arrived at a certal enter of the earth. ch thefe latter i which, when they hich they tend to the ¢H affected. . . : to the gravity by ith how prepipuation 3 nd for this pur- Hence, if the parts of the diffolved body be fo denfe, or Thus we may con learer by an example that which refults be capable of having fuch conta@® with the parts of the {o]- il This will become compound, fuch as : ¥ From experi- vent, that the activity of thefe latter parts thall be entire] ofe, let us ghools R itrous acid with filver. this compound, fatisfied by their mutual union ; the folvent wil] then be in : De the union of n hen copper is applied to ith the coppers a ftate of reft, or in a kind of equilibrium, and will have no : ence we know, J the filver to combine gon {ilver thus more diflolving power. “This is called in chemiftry the fate or 1 the nitrous-acid Sise a new compound ; an point of faturation. To make this faturation compleat,- each 7 with which it form of the integrant parts of the folvent mut have met an inte. r fuppofe fubftances wh {f the d contaét o 1 from this acid, by the prefence an copper, Hy m tas 3 feparated ro grant 4 i ————— I ———— ses GRAVITY €opper, has no longer any adherence with the acid, unites again into larger molecules, the mafs of which becomes fo large, that they canno her tendency than to the general gravitation which all bodies of a certain mafs haye towards the center of the earth ; and accordingly we fee the molecules of filyer fall to the bottom of the veflel in which this operation is made, | fay, firft, that we cannot conceive what happens in this operation, unlefs we fuppofe that the force which unites the parts of the filver with thofe of the nitrous acid vanifhes, or becomes ineffe¢tual, in comparifon of that force which tends to unite, and which does unite, of a mutual and conftituent parts of the denfity and Contact of thefe fame parts ; I fay, that if in the prefent cafe, the parts of the nitrous acid quit the filver to unjte with the copper, the integrant parts of this latter metal muft have in- finitely more denfity, or muft be capable of having a much more’ extenfive and intimate contact with the parts of the nitrous acid than thofe of the filver. Whence the action of the parts of the nitrous acid, which is only very imperfectly fatistied by their union with the parts of the filver, is in fome meafure exhaufted by the new union with the parts of the - €opper ; fo that only an infinitely fmall force of adhefion tq the parts of the filver remains ; and then we may eafily con- f the filver to each overcome this flight fequently the parts of filver may really fe- parate from the nitrous acid, and may form fenfible maffes capable of yielding to the general gravitation to the center of the earth. Hence alfo, if, at the fam ¢ time that the parts of the ni- ous acid are determined by the prefence and contact of the parts of the copper to feparate from thofe of the filver, thefe parts of filver thall find vrithin their reach fome other fub- neces, with the parts of which they have a ft]] greater dif- pofition to unite than with each other ; they will unite with this fubftance, and form a new compound ; which circum- fance ought to facilitate the feparation of filver from the nitrous acid ; apd which alfo, when the filver has a ftrong affinity with the matter prefented to it, might effect the fame decompofition, although even the Copper had not a fuffi- ciently ftrong affinity with the nitrous acid to feparate it from the ‘ a bination: e have made, fuppofitions fequences 0 ‘ refer to the a i SITIONY d matter PRECIPITATION, at this interefting difficulties 2 oy co bo ie 1:81, gn mu Jems ry will herea % H miftry, ) x Je jet of which n Pot hidden phenomena © GUMS +n the cafe of two ly to happen \L © only This fears 8 AR ination, which ¢ ofitions a ; . 1 com- ities. in chemica double affiniti wih happen io duced from the r phenomen ay be eafily {lary con- : compoiitions ng: only the nece ena, We agra henomena, ofitions. For Compo- £ thefe fupp INITY AGGRE N. SOLUTION, ticles ASS DEcoMPOSITION, ION, ; . t Couminaty PRECIPITATES s liable to grea e erficially treat- yop fone 5 &i d is here but fap 9 a in d in mathematics ch more light pon have but confufed hs s the true onfider them 2 equently of 1 cannot but © e chemiftry, and confequ rk is the alchemical all matural pilk Eg. The great WO ded to be made. LA reten hich goid 19 (£4 ich feparate ee T-s TON B ( J jutees A hens Gums arc ants or trees, he greate GUMS. ral plant rion of the g {pontaneoufly Somber by the oS ormerly all copes P uired a folid co bundant water. ature Was, be Ho tever thei d from trees, wi fe juices, W opals juices collecte Hence many of thele] fuch are gum cop . fo “called EO ois are ftill called gums; many others : bu d i f mma gutta, 73 jety confide “or partly re nime, gumma g with propriety m elemi, gum a d naturalifts have v " ifts an as true ang ‘ le in water as ie modern chemiits © te mucilages fous of thefe gums only 1 ed only the “We fhall therefore trea pure gums. degree his peel vea firm and folid expen parts. a ol Le Gums ha t tenacity of (8 PL ifon f elafticity, and en capable of refiting pe very difficultly roperties render the hich they are ren Fen broken ; by Whi a certain degree cles of fand 2g- 3 from . art a ftone confiting of P Ei c - ‘hele tones proce §., 4) Grit T-prax The diffsrentes 9 ns thet, WE | ther. icles oi 1anC LU t degre : lutinated 10g¢ he partic differen loye a different fizes oh ole Tands, and oe fiopes g1e SBP feel oat properties Oe Some Ness for whetting fharp : , t agg . din , ot ; , altnels and 0 s for grinding ater. erifable “for bila gs his im filtrating W pulv “jnftruments, ‘ -pulverifablein a trandi 3 mortar. T Canfpent: ome of the, nevrtheety we po hc foreign to 7 Moki ie matters by which x " any tafte, or a ver ery pure gums have ey are colored are foluble either by oil mild and flight tafte, fmell, fearcel sy Or by fpirit of wine gy They are on) » Sut are perfect] y foluble in w ater ; r; and when the quantity of water ufed for vifcid, t ’ ranfpar . fuch as parent fluid, and s the uid, and the . y were originally, Y again become mucil ages > Althouch of very 3 3 guns are obtained fro fimilar, EE 2 i, en the quantity of koe properly differ peverthelefs, are ver with water, Three tage which they are cach other but b ed. Thefe are ar kinds of ps of forming Sum tragacanth I nen a ppvnuralls ng which iiues from a thor ( inary gum yn yp Sis ny fhrub call ” of fi 1 Syria and ot! rub called traga- broken, are ee! twifted bits, orenyal countries dearer than g. It contains ces of which. when Gum 2 ny other gum more mucilage x en ra $ + * ’ n { haps from fe Oitaing from a kind of i ® Africa. It confi ny er trees which oro acacia, and per- are bezatifal. whi s of round, rough grow in Arabia and i Ordinary Ato and riper: pieces ; fome of which fruit-trees ; Jus ax mob which are oath trees, &c. They a almond, apricot ol ered from moft rent than gum arabi ge generally lefs and cherr ful. Druggifts pick $ Dough fometimes pe lefs tranfpa- them for gum arabic; e beft pieces of thef: y are as beauti- ceeds, as they do ¢; from which no i e gums, and fe]l Asgum ary San effentially differ fr SpRanvaiens pro- united with a ge are only one and at gum. thefe matters Senter or lefs quantity A the fame fubftince their analyfis fur ieunly the Jains perabundant water nifh. the fame principlos, © For 5 hu in ‘ or a further knowl edge th : , therefo article MuciLac re, of the nature of o E. gums, we refer to the GUM-RE ad 4 SIN cilaginous and part] By Sun-rofing afe iui trees, and which be y Ol Ys which flow oh ces, partly mu- finch Jud parts. come concrete by the ba kinds of I'he oily and mucilagi ation of their are intimatel . ucilaginous parts . other ; Tately muved, but not RC gum-refins concrete {ubftances are ined with each not perfeétl foluble, y trees and plants are of a yellow or G UM-R ESINS or by fpirit of wine, fingly- for example, water, is and when the action of kind of {olution is foluble in water, an part, whic foluble, either by water, by oils, When indeed any of thefe folventss lied fingly to oft gum-refinss {uch folvent 1s affifted by trituration, 2 is entirely ; while the refinous d intimately mixed with the {ufpended in the water, and confe- kind of milk or emulfion : but this oily part dently divided only, but not diffolved. See m-refin is reduced nearly to its Thus the gu , becaufe the oily {ubftance lofes I fay nearly # fluid and volatile part, ng it with water 19 t EmuLsION. original {tate ; ‘by drying its mo ftored to it by wreati mentioned. We may alfo make a kind of {olution of t by employing {olvents, which 2r¢ partly watery and partly oily or {pirituous 3 fuch as wine, vinegar, of aqua vite: but thefe folutions are always milky, from the water which hinders the {pirituous part from combining atimately with the refin. To diffolve, therefore; completely 2 gum-refin, the gummy part; by which is not re= he manner above- hefe gum-refins the refinous part muft be feparated from applying alternately 2 {pirituous menftruum, and a watery men{truum. From thefe properties of gum-refins, relating to their folu- bility, chemifts have difcovered their true nature; for from moft of their other properties, and particularly from their external appearance, they might be confounded with pure refins, to which they have a {trong refemblance. Here we ought to remark, that the proportion of the gum and refin is not conftantly the fame in different gum-refins, in {ome of which the gummy part is very (mall in proportion to the refinous : hence, upon a more particular examination 0 the concrete juices which iffue from trees, many of them are clafled among the gum-refins, which forme IY had been confidered as pure refins ; and this fubject is- fia certain. Neverthelefs; as all gum _rofins are mixtures © fubftances which are not mutually {oluble by each other; and as from uch a mixture the compound bodies Which refult muft be opake; we may difeover, merely b ew’ whether any concrete juice be 2 gum-refin or not. thofe which are opake, or are not evidently tranfpareint; may reafonably be fufpetted to be of 2a ummy-refinouss of ex tractive refinous nature. Of this kind are myrrh, bdelliumy Jagapensms opopanaXs offa-fatida; and others which a ah ently GUyvyac On the cop trary, all thofe' which are y be certainly confidered ej}, SUMS or pure refins : fuch are the and the pure ref €r a diaphanous fubt, dently gum-refing. S$ pure 8Ums ¢{ragacanth and NS maftic, fandarac, nces, which be pure by their fmell, 0 oily matters, in determinin ought not to Prevent us from m and particularly thofe by when we would ¢ to be examined, thofe concrete juices which ftrongly colored. Such are guy. draconis, aloes, opium : for thefe ] juices are ill more compounded thay pure gum-refing, and contain ifferent coloring and extractive matters, See O1Ls, My. CILAGE, Extracts, Emursions, Gums, and REsins, UN-POWDER See Powpgg, GUyAac. i wood of a tree which grows in the Antilles Iflands, and ; contains much refin, which may 1pirit of wine, in the fame manner turpentine, &c, may be extralted fro contain them. uyac wood that of boi]i lacy, gumma gutta, [anguis atter concrete jy; ; guyac is to be difti]led ngs, and put into a flope. adapted a Jar ze glafs receiye fide ; and dj illation js ware retor t elt a liquor, almoft purely water, then, re, an acid Pyreumatic reddifth oj], at the fame time, a ir is dj g > Which would burft the receiver, if Pe through the {ma} hole, which is fometimes opened for that purpofe. The acid and oj] continue to rife thy to the end of the diftillation i the Rest bik —— he wr —— 1" 5 GUYAC il becom» and the oil ing ftronger and frongehs ck, and thick; fo the acid becoming re empyredmatic; 126, of Sa mo x ua diftilla- y re and fiftence 1s eq d-hot, the ing mo ft. its confiften horoughly re ’ ac are i t lait, t 1s tho os ings of guyac that, 2 | the retor the {havi g . inal when e retort, ; ain their orig 1817, finifhed. In oe coal ; but fill Team d the oil are Yom d reduced fo pe called alfo the Soir 2 feparated from form. Toe a the receiver, and may des oak Cc . e nd toget 1, chemifts, ‘3 fo other by 2 rR is well Kowa. by of the firft which This analyliso od produced was ation by mixture wit the empyreumatic capable of ipfiamn fis is generally ge was obferved to isd becaufe this if vegetables with a nake Cs itre; a iftillation of v iric of ni diftilla . fp an example of the ; s plants from which 11 the odoriferou latile principles, Thus, for i effential oil, an heat not exceeding that the {pieitus seRiofy Stems ee a ith a paked fire, CBC wards ditti icld principle have been being after fed, yield p * hoiline water, be decompoicd, ; of boiling w h they cannot avec Wood, d . . a ac~ witheis RE obtained fe Bor i v8 alogou ac WOoogQ CX irdifengaged dur ms analyfis og great quantity Spero that this ele- {ferving attention. ery remarkable. ap and particularly in thls operation is bial in certain Bodie, are difunited Jor ; ly com its integiant p ‘vod parts of the ment 18 tru ( that its intcg f the unitea parts . to 1ay, {ome of the : hich the is ; thats ere to iom ime during w : gs other, and ona by the long hme 3 ait being “hi . fo Li guyac. 1 a from the guy % eas root combined sp 3 1c g 1 oy ity 8 nied, air difengage latile than water, hich it is u volatile : ~iple to whi h lefs than much more fixed principle heat muc . ome d with a nt and un- retained by tH n aged, an " erabuncan {oon dt € g aife the {up 3 ‘ {i ems to be would be : ‘1ent fo ra 3 Pa this alr 1€< . hat which is fuffic _guyac. Befides, t this compound ; : bined water of thc g hile it remains int {mall a fpace, a of its elifrely we condenfed into b bi Fithe onlin € oh’ 1d no is privatio Eom t cou But this p 's broken. in but by a violent al{o that its hind fire, has city of the air De ihe, phlogifton, : are properties effen- ‘the fame oem nor fluidity, a: - fols neicher light, it is in its ftate o BT a naked fire fr tial to it, NheA ined in ae united, and even in The wcid o fimilar vegetables 1s foil This appears fron By ne ae confiderable portico imately, wi : Vor. IL GYPSUM its color, olor, and particularly from its empyreumatic fmell 3 foi this fmell cannot be contradted by any thing but oil : befides, the acid may be deprived of much of this émpyreumatic oil, > further ‘operations, and particularly by faturating it with alkalis, from which it may be afterwards feparated by a fecond diftillation. In both thefe operations much of the oil is feparated, and thus the acid is re@ified. This portion of empyreumatic oil is found to be well combined with the acid after the firft diftillation ; for it no longer difturbs its tranfparency, even when it is mixed with much water; becaufe the acid ferves as an interme- diate fubftance to keep the oil and water fufpended or dif- folved. : This rectification of empyreumatic vegetable acids has not been carried fo far by chemifts as it might be. The oil ‘obtained in ‘this diftillation is acrid and e ‘matic, it being one of thofe which are in diftilled butby a heat much fuperior to that of boi ling water, by which heat all oils are much altered, acquire a burnt and empyreumatic {mell, and allow much of their acid to efcape. See O11. Theoil of guyac is employed, as all thofe equally acrid, to facilitate the exfoliation of carious bones. Laftly, the coal found in the retort isa perfect coal, when the diftillation has ‘been continued till the retort has been red-hot ; otherwife the refiduum would contain fome thick and half-burnt oil ; but it is ‘contrary to the nature of coal to contain any oil. See Coal. GUHR. (¢) GYPSUM. Gypfum is a foft, friable, ftony matter, which does not ftrike fire with ficel. Tt is found in large ‘quantities in many parts‘of the earth, forming large moun- tains, and very extenfive chains of mountains and hills, as in the neighbourhood of Paris. Gypfum is always cryftallized, or regularly difpofed. In its cryftallization it affects feveral different forms. The firft form is that of large, tranfparent, thining, thin lamin mpyreu- capaple of being (¢) Guar, Cretafluida, Medulla fluida, Marga fluida. Thofe names are given to a liquid calcareous or chalky fubftance, white or afh-colored, found generally in mises and fubterranean places, where it drops and forms flalallitical concretions. There are alfo metallic gubrs, or’ liquid 'm.fles, fometimes found ‘in mines, con- taining metallic particles ; and which, by dropping, form metallic Rala&lutical concregions. : applied .appli GYPSUM i {les that they conftitute ma % Sh are called by naturalifts, heir large fhining furfaces, like thofe ed to each other, as tranfparent 2s ery lapis [peculartss from A 3 is £5 d le fecond place, a large quantity of gypfum Is found n the : appli itudinally to ‘ke threads applied longitu yi Gi baled Siriated gpfum. Yielye 3 oy Eh f gypfum is found in fmall i ar 2h 5 large quantity © h. other, forming confiderab 5 i id agglutinated i! ranulated ftones, commonly ca a boas i Be are very white and pure, which g i dba cil and perfect femi-tranfparency. them a m sppern. IL very different inexternal ap- . thle gyplims SEE? as 2 their chemical and effen- pearance, Ha] to a very moderate heat, they quickly lofe en ex 1 .~ They uire an opake white color ho TRA A Ys expofure to this Nays * the Be Hr) Japis fpecularis {eparate from each he pias of te {tate, mixed and kneaded » D i - pI of mortar, which foon hardens ne a foli Soi Pipes : renders it very ufeful for buil ings, jams bls: i which it is” employed under the pat gros conftruction in fa&, nothing can be more conven y Wo He which in its (oft ftate is capable of receiving an] a fton gypfeous n external refemblance. wT i ae ® efermbles calcareous erp Oy wll hs and put into water, 2 pellic e i Lg ip) oe is formed upon the furface of oe we. T ET Ee the fyrup of violets green, as lime-w 1S ¢ - i kes d Laftly gypfum acts a little upon fulphur, and ma OCS. ’ f ioned, a rhomboidal fams above-mentioned, Ao () Be Roe a alfo felenites, fome ime} Taming ypleous os not. It is diftinguifhable from 1 on a Te yo by the general properties of gypiees Seas Toc fae I fums are s © : trnaied A0E1CY aly as hexagonal parallelipipedons and py+a ren mids. it E 2 GYPSUM it a kind of earthy hepar of fulphur, as quick-lime does ¢ but, neverthelefs, gypleous and calcareous ftones ought not to be confounded together. Gypfum differs from calcareous earth in this, that it does not diffolve and effervefce with acids. Mr. Pott obferves, that vitriolic and nitrous acids being treated with gypfum, do not lofe their acidity ; whereas thefe acids are eafily neu- tralifed by calcarcous earth, with which they form neutral falts with earthy bafes. Mr. Beaumé remarks, that gypfum may indeed be diflolved in fome meafure by acids ; but that the gypfum, thus diffolved, is afterwards feparated by cryftal- lization, and is in the fame ftate as jt was before that folu- tion, without retaining any part of the acids. Befides, quicklime does not harden, as gypfum does, without addi- tion of fand or cement. Thefe differences are fufficient to diftinguifth gypfeous from calcareous earths. But this diftinétion is further efta- blifhed by experiments which have been lately made by chemifts to determine the nature of gypfum. Mr. Pott, in his Lithogeognofia, places gyplum amongft the four principal kinds of earths, to which he refers all the others, and confequently diftinguithes it very accurately from the three other principal carths, and particularly from cal- Carcous earth, He relates in that work many experiments made upon gypfum, to thew its nature and properties. Gyp- fum, according to him, cannot be fufed without addition b the moft violent fire of furnaces.. Some chemifts had affirmed that it was fufible by the heat of folar rays collected by mirrors, Mr. Pott did not repeat that experiment, I have expofed lapis fpecularis to the focus of a good burn- ing mirror; and I remarked, that while the focus of rays fell upon its flat furface, the flone was only calcined, and not fufed ; but that when the focus was applied to the fide of the ftone formed by the edges of the plates or laminae placed upon each other, this gypfum was immediately fufed with a confiderable ebullition (g From Mr. Pott’s experiments we chiefly learn, that gyp- fum or gypfeous alabafter, (for that was the kind which he made the fubjett of his experiments) may be fufed and vj- trified when mixed with argillaceous earth, to which jt / (2) From Mr, D’Arcet’s Memoir upon the Effeéts of violent and long continued Heat, we find that al gypfeous ftones and «earths are fufible by the fire of furnaces, ferves PSUM G.Y th does : bu t in this fufion bubbles and {wells a much a flux, a8 calcareous G38 ferves as | po : careous Sos al ure calcare Er ty ca os "T is 1 of Sef 2 ropert mmon "? gy 2 ne Lone a bv the greate pus of oe Bs fed of calcareous €ar 3 jc d Ee united in this Sp, A in hi ir in his Memo on Qs. M irs O : : the Memos J +'.s ofic hed sminghy the vitriolic acid as me the year 1747, {umm i rts of EYP that fev: of the conftituent ogeognofiz, Fs | refulting from . Pott, in ni gs a CO . and that Me k amongft gypfums h a calcareous earth ; Tr or f vitriolic acid With: earth, of artificial &¥Y) this i lenitic ? ~-o5 betwix the union Of mpound felenttic ferences be they call this CO go d fome flight Se former had all the in his Elements Although Mr. Pott foun et fioned by 2 ound and I! atter. bal properties of the | f hard waters, on eer, treating of Bars Woo. 2 Mr. Macqu fays that their har n them > Lia iin bia ji od diftilled SH true le fulphurcous 207 tartar, DY x 0 La havin treated it with the pe it a vitrio- avi ain ; he the RR > bteouy 3 hae os he arti- Jiedty Tt 3 Sat Fhe sere ter ; i 5 cous lated tartar; irely foluble In War > 0 cid with calcareous : plum is ui ivy (zturating Vitrio LY e - OnN- cially compo Dif. has been dem ent. 1 m has : carth. Opufe o i that EYP rth faturated with Wel in elfe than calcarecs bafis of calcareous fated 1p pea 2 a vitriolic falt Wee SELENITES. _ vitriolic acid. F.C ie felenttes- 2 he properties © th: that is, 1t1S explain 2 os cryftal- earth ; that its tranfparencys oli ao chats ypfum. water, proceed roms becaufe it 18 lation, not be combined with any pi requires much t can ; Te. By faturate b ee water to diffolve1t y of eart . . . al that is, Go which thas hich the ¢ and the wt 1ts calcination, Y han the vitriolic aciG. hing elfe t i t parts are deftroyed, 18 pov 3 t feveral Au- fulphur; d with the vitriolic ac os felenitic quality 3 ds fro which it contains, th is united with the ohefion of its fubftrattion . of HARDNESS of the water of jts cryftallization, §,, CrysTarriza. TION, ‘The properties of quicklime which gypfum acquires by calcination, ought alfo to be attributed either to the fuper- abundant calcareous earth which it may contain, or rather to the fubftraCtion of a portion of the vitriolic ac; is difengaged during the calcination fome inflammable -matters with which this acid unites and forms fulphur, Laftly, the hardening of plafter, when cal- cined and mixed with wa may proceed from a mixture of m refuming the water of its cryftallization, and again cryftallizing precipi- tately and confufedly, as many chemifts think, and parti- cularly Mr. Pott, who fays, <¢" As plafter mixed with water *“ does not harden, but when j¢ is left at ret, (for if it be “¢ ftirred too long, it will not become hard) we ought to conclude, that in this cafe a cryftallization very fudden] happens, which confequent] {fuppofes a very divided fa- line fubflance, uniformly diffuloy through the plafter, as Stahl has obferved, alfo is the reafon of the want ili the air ; becaufe the air alters “¢ and attacks the faline {fubftance which it contains,” Some chemifts and naturalifts have given to gypfum the name of par, or rather diftinguifh a kind of {par by the appellation gypfeous ; becaufe this {par has the principal pro- perties of gyplum, = See Spar. ¥ ARDNESS. Hardnefs js a quality of certain bo- i dies which confifts in ap intimate union and ftron adhefion of their integrant parts, which cannot therefore be eafily disjoined. We cannot precifely determine what difpofition of parts occafions the greateft hardnefs - but this probabl depends on the perfeGtion and extent of the contaét of thefa parts ; and this quality depends eflentially upon their figure, which we do not know, The hardeft bodies which we know are vitrifiable ftones 3 and amongft thefe, the hardeft are thofe which are the moft pure and homogeneous ; that is, diamonds. N ot pROMEL etd: Per- wn bodies is SL elemen- doubtedly to the z all beings We of matter, w {s belongs MY Not any ftituent parts | dne fect hes con and HOMOGENE- . and ¢ different Natures; and en US. Heterog & rk Pomogeneous ago el is honey dilated po fer- HOPES MEL. Br this Moat it has under- I ter. : w Wl AY weight of MN nl bydromel i Ci called the vinous 2) mented, It 18 ; mentatio ’ ‘rituous fer onc the {pint ; > ances, veg & rome, gf Tike all faccharine a: an Honeys) 5 fermentation To induce this 1 is fufcepti € fermentation: eh {ufficiently 3 ae OF the prions ary but os u a convenient deg sellebore ing is ne to bite be g Sa this liquor spl ounces of the or exe 3 ORE. VT amsand a foruple init of wine feve bh) HELLEB r. INE drams 2 1ded with pt + of black . with wateT, root yi€ s of the root foe fame quantity of From fx © “exura : drams of I s and a fcruple We and two g willed water of or pou fame quantity 2. 6s Hawes, &ed by water. fle fe s red; pom whole plant pofle or Blo ; als doy t NH MATITES, the pow fometimes P . 7) Jie 3 DA ee gure, and fometimes TPL J] : mediate SEE Mae ths apices of which fometime or fmall, the imal ble or animal, Cp cularly of is fermentations, n water, 4 3 heat. : 1 ins 2 large femi-fpherical, P ramids g€ Heradly iy . i € comb; confifing <1 fection, or ar metal have eR fach in a tra ds of this ES 7 obtained Wil porn of ro EPO he rom 5 SHINS Coponty Dr a quintal of the bad a quality> {hat th renders it fit 10 BE : and 1s of fo Bult of hematl The grea: Ne tals. i fmeteed, d polifhing esas . uors, and are {aid > ra See Lav dded to malt liq els vifcid, and able 2 Hops are ufually & t to become four, fu fe liquors 16 °b_ se bitternels. 0 by pe promotes he vd Tightly boiled in WOTh HORN To make good vinous hydromel, or mead, the whiteft pureft, and beft-tafted honey muft be chofen, and this muf] be put into a kettle with more than its weight of water ; a part of this liquor muft be evaporated by boiling, and the liquor fecummed, till jts confiftence is fuch, that 4 freth egg fhall be fupported upon its furface without finking more than half its thicknefs into the liquor ; then the liquor is to be [ ed through a funnel into a barrel : this ght to be nearly full, muft be expofed to a heat as equable as is poflible, from 20 to 27°or 28 degrees of Mr. Reaumur’s thermometer, taking care that the bung- hole be flightly covered but not clofed. ‘The phenomena of the fpirituous fermentation will appear in this liquor, and will fubfift during two or three months, according to the degree of heat; after which they will diminifh and ceafe, During this fermentation, the barre] muft be filled up occa- fionally with more of the fame kind of liquor of honey, fome of which ought to be kept apart on purpofe to replace the liquor which flows out of the barrel in froth. When the fermentation ceafes, and the liquor has Become ver vinous, the barrel is then to be putin a cellar and well clofed. car afterwards the mead will be fit to be put into botties. or mead is an agreeable kind of A The vinous hydromel wine ; neverthelefs it retains long ga tafte of honey, which is unpleafing to fome perfons ; but this tafte it is faid to lofe entirely by being kept a very long time. ~~ The fpirituous fermentation of honey, as alfo that of and of the muft of vinous liquors, when it is 1s generally more difficultly cfteted, continues longer, than that of ordinary juice of grapes ; and thefe vinous faccharine tafte, which fhews tha become fpirituous, The caufe of contain lefs acid, or that they con than the muft of ordinary wine. INE. HONEY. Honey is a faccnarine fe leéted by bees from flowers. honey fee SUGAR. HORN of ANIMALS. The horn of animals is of the fame nature as their gelatinous matter, and is only that matter charged with a lefs quantity of water, with a larger quantity of carth, and {ufficiently condenfed to have a firm and folid confiftence. By digefting horn with water in Pa- pin’s digefler, it may be entirely converted into Jelly. fugar, very faccharine, requires more heat, wines made from the liquors always preferve a t a part only of them is this probably is, that they tain an acid Jefs difengaged See FERMENTATION and rmentable Juice col- For the nature and properties of Horn HORN-B LEN > in dif- 1y animalifed matters DG tteres that 18, ns Horn is 2 perfect Y ciples as all animal ¢ not exceeding tha hr n the fame pid ith a degree of hea {pirit, which be a pure phlegm, with £00, Alkaline oa fetid, lights he boiling wa 1 more penetrating aad jy forms am C3 ! re an latile 1alt, ir ; fet 4 Cin oh 2 cones Oe "ch aes KE os ns upon the fides and more black it of almoft incom- tio .h becomes more confiderable quan Y eration; {carcely Tt leaves pie p ‘om which, after its inc firlt in I ‘oal, from ined. a rit 1 buftible cali can be cbeained that which 1s Sn. great ny fixed alk: d particularly PH 0 TE acquiring : Swim) oil, an i 1s fufceptD ations, and is then the diftillation Xo by repeated a Ie : d vo ' that ariickes A of Dippel- a i other io be retifie calle f {tags, “Mh the animal © The horns © to furnifh t hey ¥ : moft proper iy 1; becaufe t y i - manner of De differ from the uantity. is, that they cons . hence = mals in Bm «hy which is in pouss 4 horns and bones. fame kind 0 pnediate asus SCINED to W offefs an In RTS’S) Toh ) HORN (F { nlogifton of ib may 0 NESS. oo difficultly combu 1of other horns, 20¢ though very re eafe than the cod This coal, by burnt with Boe facility as bones may front fire, not) 3: iy a long ir i AA calcine calcined W ite earth called ha edicin into 2 id is employed I als whi nefs. . ind fenteries and a fled matters. It is given 1 b y ed and jil-diget d is the bafis. to be wi ae and Jorge ly prefcribe "calcined to . which is ¢ ham’s white decoction gD PHILO Gifs N icalv H his name 15g . 3 ¥. 7 38 inous part; | PHIC ALLY all its AEE 0 by waier © d when its outer par ble to the bps ery white, and 1s applica : v r fire. WA is ‘calcined by re (m vw HORN-BL END. HORNST . or reen : - a, le fro ) HoRN-BLEND 1S a plesk of 3 JiRinguifhab Mm confifting of fcaly particles, 1s of that kind, icld the Jp horns of othe antity of the T hefe Horns @ contain a larger Ss ym to HITE- art’s-horn, al helefs be evert ”! wih ng 1s changed d to white- e as an abforbent. of Syden- d in theie §O- hart’s-horn deprived {o that it becomes ff. it is thus ren= 3 es as that {fame uies a EIN. lav 1 1 or Cid) indurated oi€ Be thofe ot HORNST JE LLY HORSATEIN. (= ACINTH ThpAP, + See HYACINTH. NIC E AsPER, (i) (© Y JELLY. PCOLLA, See ISINGLAS capable of forming kind any ve etables mucou S. 2 s of jel y are obtained ; § fabiiences » ele are of mica, by hei of mica, by being lefs fhini generally found g lefs fhining, thicker x TH Ee 8 fone and ak I: is x ORNSTEIN pact lone, es Intermix erman Ra Rene lex Wallerii, Thi Ho Sr Crit e filiceous fto 1s name is gi (0) H z. ne called in Tel cr by | HYACINT chertz, aes re or lefs ed Jacinta, is a preci : egree of hardnefs f; ent, of a yellowifh r gus ftone, polygonal (2) Java. Saiom iseonds, and fu Io colons the ninth in wine extracted five i ixteen ounces of oor by fire. and from the FETs ess and four fcruples ‘ jalap, fpirit of gammy-matter. This root is obfer Dy ay refinong sasty: ; in promoting the fpiri oot is obferved to have unces and a half of as of melafles. pirituous fermentatio a confiderable pow: Ca Neanan. n of {weet vegetable power PAN-EA ‘ juices sea, obtained by nfl Yh name is improperly oi ’ of a certain palm-t piffating the juice Hg Y givep 10 3 gum. mmol entirely ae wie grows in Agi o the fruit ane. Its tafte i y W en pure, b ndies. Iti agreeably os. * New firft bitterih As ews or by fpirit of of this tree into {mall man. The Indians are r and 1s afterwards maritime plant beret pieces, which they wra faid to cut the fruit thefe balls, the i, together with fome 2p fhe leaves of the i ¢ and {mell of whic ge and to chew r) Jasper i iY y find to be ve green, red, ior opales filiceous fone, of vari y of different colors, Sa or variegated with foots colors, white opake, in being a, t differs from flints a Fr with veins Jared texture, and a eafily fufible by fire : [ena in being Noereas flints and Coty ntly compofing ice ir 2 Sram ps. Fro . <4 are ene 1 . €s, or rock - fufficiently oe Foams jafpers, ot m ah onet m of nodules id Lor ta Jefe . Gre fora Bo receive and Sots. They are Aare ca afi with fpeck ¥ ne polith Ja/poryxes pecks of onyxes or po ' agates, they more yeLLY ed mucilages and g tter 18 particularly app from animals. : mals feem to be chiefly compofed For if we boil in water, efh, bones, a word, any nerves, horns, {kin, 0 ich compofe animal bodies, this water, the liquor by . If the evaporation be but with a heat incapable at firft a glue, and after- of decompoling this jelly, it forms wards ‘2 horny (ubftance more OF lefs tranfparent, hard an folid. The blood, fcarcely any thing tains a large quantity © moft all animal 11quors, ums. The name ell licable to the mucous nimals are Milk con- al fluid of a oO as urine and fweat, are ut kinds of watery jellies. ght to conclude, that the gelatinous matter e animal (ubftance. 1t conftitutes als; itis that which nourifhes, repairs, and re . itis inthe animal kingdom, what mucilage is in the vegetable kingdom, from which it and which it refembles in many of its feems to be derived, properties. See Gums and MUCILAGES. ly any {mell, of | ftate has fcarce y. Its tafte is fweet and faint. d by the help of other circum- ftances neceflary to ion, it eafily ferments as foont as it 1s deprived of vital motion, metimes even during the life of the animal to which it belongs: It occafions feveral difeafes, and confiderably deranges the animal eco= nomy. At firft it tends flight! the acid fermentation, be obferved in ‘milk, i in flefh, and broths 3 kly to a compleat putrefation, as may and then it pafies very quickly id liquid (ubftance. See FER- which reduces it to a very feti ENTATION and PUTREFACTION. ~ When it is Very frefh, and expofed to a degree exceeding that of boiling water, nothing rifes its fuperabundant phlegm, of water. BY lofing this fuper- abundant water it becomes and -more gluey, an at length acquires nearly the con n. In this ftate, when it ha than this kind © ¢ fuffered no other ] drying, it may be again diffolved in Waters and refume 1tS former liquid gelaginous fats: Nevesthelelss INDIGO Neverthelefs, fome gelatinous matters, fuch as the whites of eggs, and the white part of the blood which is not watery, are coagulated and hardened by heat ; and thefe, when once well dried, cannot be again rediffolved in water, or at leaft without great difficulty and particular management. Acids and alkalis, the latter particularly, attack and dif- folve jelly, with great éafe, The refults of thefe combina- tions have not yet been fufficiently examined, Oily fubftances appear to have no action upon gelatinous matter, Neither can re&ified fpirit of wine diflolve ijt. ‘This fpirit does not a& upon it when it is dry, and only takes from it part of its water when it is liquid, and thus coagu- fates it. It then appears a precipitate compofed of little white flocks. To this property which fpirit of wine has of coagulating jelly, is with much probability attributed the thickening of the lymph, the ftuffing and breaking of the lymphatic veffels, whence extravafation and dropfy follow ; in a word, the principal difeafes of thofe who drink toomuch of fpirituoys liquors. When dry gelatinous matter is expofed to a degree of heat fuperior to that of boiling water, it fwells, rifes into bubbles, emits an acrid, empyreumatic, fetid fume, and is with dif- ficulty, and not without a very violent heat, inflammable. If it be diftilled in a retort with a graduated heat, at firft a little phlegm is obtained ; then fome liquid volatile alkali, a thin and penetrating oil, folid volatile alkali, anda very em- pyreumatic oil, which becomes more and more thick, follow in the order they are here mentioned. In the retort a con- fiderable quantity of that kind of coal remains, which cannot beburnt without great difficulty. From the afhes of this coal an exceeding fmall quantity of fixed alkali, and a little com. mon falt may generally be obtained. Thefe are exactly the fame fubftances which may be obtained from all animal - matters. As many things are common to jelly and to ve- getable mucilage, fee the word MuciLAGE. JET. (5) INFLAM- (s) Jer, Gagates, Succinum nigrum, is a black bitumen, re- fembling “fine black ebony wood, hard, light, compa&, and {fmooth. It is very inflammable, and burns with a bituminous fmell. By diftillation it yields, 1. an acid liquor ; 2. a thin black oil ; 3. a thick black oil. By friftion it becomes eleérical, as amber does. See Bitumen. (#) Inp1co is a blue fecula, obtained from the American plant anil by means of fermentation, in the following manner, | : The AT ION ROUS S by NIT mixing is one © jration . the adm . INFLAMM which ex ited pers To Tourneioity richius, r. Dov Geoffroy, and i e Co- ed in th Danifh chemift, Jl A LA . a p % factions for the Year 107% i : e , ith water. In a hot, throws up 2 becomes yO ie er iolet color. The 1iquo e or vi = on of he liquor 18 to be y fecond vat, t a Ho by flicks and buckers anges i 1 : coloring pies hn ge : fos oe Et is let off to fricks, as {obfided, the} siinirge fi Wn hepie J n drained and aric whe fupiide, ji the fediment, fire. With watef tirely confumed oh more wate? : be almoft en diffufible throvg fixed alka- may . a P Cy Ty. , means of formed Into 2 des. bJ ter. Woolen d in the above Indigo gv tieous, OF itriolic, niuro! i% ne cid unites WIR . water, : eviou! y 10 lime ids 1all od, ge n= marine aces acid, 10 joo 1nt0 2 a d when hot, 18 of ve A ' e 1 The abo o is render ter. brown. ; A dig afs through 2 g a note to his tran as to F een color, and, . aking 2 co = bright gr ts are mentio ft 3 as indigo, fee experimy man’s Works. rom lation of INeuma’ Saxon blue 2 : ofition for the YgrLLow DYE pentine Bue (saxom) ge Ys entine may be j . e inflam A _— re tht time ie) od mixing it with ni i. ma of the "i Aly Someenerited argu acid. . ent did not fi ifts who att us acid w em as famed by this 2 fiscoted. ‘Tournefort P 5 hil repeat this he ine i fays, in the M ail of faffafras : Hom 170% amed oil of Viemoir - Homberg i tu ‘ S of : €rg 1n but he fays that pene by mixing the Academy, Iw Jor 1706, inflamed a muft be thick With nitrous acid ; E . . . 2 cul perimen was cE a FreuNupic oil ysere) in the x an the o : ed of, becaufe i guyac ; an x d, and Lobe OWE) becaufe this fag: ee ind ance; namely, 1s attended mmation i y ‘th led by a 1s, vor Hig {pongy body Stem amidft the prielny Greta e {hall fee > of a confiderab ames arifes a bl; uring the i eft part of the » which is, a of guyac hi Fw inflammation. LE Be oil rarefied » 23 H courfes of chon isha to, and oS to of oil offman, a Geren ry and experimental ewn to ftudents mift, having made I ehemid, and Geoffro P hilofophy ; till covered at the fame ti any experiments on 0 2 Pranchiche- wa concentrated ae that fmoking is matter, dif- : r the inflammation ii acid, WEE acid, mixed pn which i Obgiiss and py better e then refu een almoft reli of the oi med thi : relinqui e oil of 1747, 3 Memoir ay fuged, and thes. Mr. Rou- Ri t by nitro ; many experi ed, in the yea cluding oi us acid may be i periments, which ea il of tu . y be inflamed y WIC fhew- oils which rpentine, and ed all eflential oi . are c; » and even th ntial oils {uch as oi apable of qui ofe fwee 1 oils of TA quick] i tweet expref]; be fufficiently BES Linked, hemp, Nshening and pte covered, that Ca Cones, Latie vides that the’ i thofe called fat oil 1e {weet oils leat dif Se chemift dif- their inflammatio 5, may alto be dr ed to dry, that is man and Co thn lucceed, the asad, But to ake centrated eonRIOY was neceflary ; that is entioned by Hoff. : eros: acid. Okie muft be Sr fay, fome con- eat inflammable, ciple mentioned oils Fenix with the may be inflamed b ave reafon to beli e of all oils the gp gamed by a mists of hes woes, mol, that flame is on remarks, in the aids, and when it i = nitrous acid i *d in all thefe : 1S a : 5 aCld 18 orks : refe ex- od mers of he inflammation ro on had thickened 5 Which the por- x ei}s by acids is Res hated, and dried. I'i= ment (NFLAMMATIOR formed. The following circumftances 21% be peculiar to the ‘nflammation of the fever and even the {weet drying oils, may be acid alone, provi ed that the veflel « -« to be made be of 2 convenient 1 ‘concen- acl antity of acid and oil be em~ ht to be fufficiently wide-mouthed > ater certainty, ought to be fo pable of containing exatly an ble of containing One this acid. Laftly, an the oil to be inflamed, ities may fuce nto the ve el Im le ebullition is excite dato on of thefe two liquors. The oil becomes black, and {ometimes inflames. lf it does not inflame within four or five feconds, more nitrous acid muft be poured upon - the part which appears thickeft and dryeft, and then the mix- ture never fails to be inflamed. ils of almonds, olives, rapes, and other fat oils, the nitrous acid alone. The ot been hitherto inflamed i ouelle practifes, ncentrat- have not But their inflammation 1s by mixing with them its ed vitriolic and nitrous acids, which occafio Ak and n than in the pr ances ; but when nitrous acid muft Thenthe in~ than when violent ebullitio eceding inft at its heights fome pure f the mixture. but is lefs {trong their theory iS : li thefe phenomena be furprizing, nftituent part. All oils contain P 4 alfo contains p derftand the caufe of the pow ch other. “I'he heat 1¢ {tances upon €2 gion is equal to that of ignition ; ai .even the nitrous acid being capable © confeguently. be inflamed. : 2 ullition is e thickeft part © pens, this eb eafy. Nitrous ac INFUSION The réadtion becomes more ftrong, and the inflammation more certain, when the nitrous acid is applied to the part of the oil which has already been thickened and dried, either by the nitrous acid alone, or by that acid mized with vitri= olic acid. But ought this portion of thickened and dephleg= mated oil to be confidered as a pure coal? And ought the action of tue difengaged nitrous acid upon this thickened oil, to be,compared to the action of nitre detonating with coal 2 We cannot be ealily perfuaded of this, when we con- fider that nitrousacid, however much concentrated, when not retained by fome bafe, has no action upon any kind of coal, even when heated as much as poffible. See DETONATION ef NiTRE. The effect produced by the addition of the vitriolic acid, may be explained in the following manner. This acid does much promote thefe inflammations ; fince, on the one hand, it makes them fucceed more certainly, and with lefs dofes than can be done with the nitrous acid alone ; and on the other hand, fome oils have never hitherto been made capable of inflammation without it. But although this acid ads powerfully upon oils, it cannot fingly inflame any of them. Mr. Rouelle, confidering that as the vitriolic acid is eflen- tially ftronger, and has a greater affinity to water than nitrous acid, believes that it renders the nitrous acid more capable of inflaming oils by dephlegmating it. Probably the vitri- otic acid may from this caufe facilitate the inflammation of oils ; but has it not alfo as great an affinity with the water contained in the oils, as with that contained in the nitrous acid ? and may not, confequently, its power of facilitating thefe inflammations proceed from the dephlegmation of the oils, as well as of the nitrous acid ? INFUSION. Infufion, taken in its-moft general fenfe, confifts in placing compound bodies in a liquor intended to be impregnated with fome of their principles, either without heat, or with a heat lefs than that of the boiling liquor. From this definition we may fee that infufion is one of the principal operations of the analyfis by menftruums, in the fame manner as decoction is, ‘of which infufion may be con- fidered as the firft degree. Infufion may be made in watery, fpirituous, oily, acid, or alkaline liquors, according to the nature of the matters to be infufed, and of the principles intended to be extracted. It is neverthelefs practifed upon vegetable matters only, and almoft always for the preparation of remedies which are called infufions. Aromatic are enerally | which their yirtue conliits, \ BNE. cable matte is adr forous vegetable matters Aromaty Dd when their odoriferous i is at ar be diffipated and loft by the . d, in CHR i an | : be pre me {o volatile as ie #11 better thefe volatile heat of an oil of the nature o Harter Thofe in f whieh the {aponaceous extraliive mt called tinctures reateft par by fpirit of wine are paruce the fpiritus rectors fufions made Y Macy: Oils diffolve the *P efpecially 1n P ids and A any oily mat Aci alkalis diffolve the earthy ters 2 d almo of vegetables, an : fbi difguite thers alg, {heh | bly their viriess by the ¢ # Dr fe kinds not much 4 ed for ett: 1 thefe infufions which may d by infufion a for Writing Lysis, DECOCTION, EXEC. 0 iy black, ufed for writing INK. Ink is a liquors inks are of ot Nevsrtieleh hi ink is an infos of 2 hit 1 ifts ; fial vitriol, know nto drugs) fe and to Shem ka 8 De hy win “The following receipt makes g I pene f commen water oF beer leta pose Epes ee De afed twenty=four hours without i 3 to Shee alls be infufe f gum-arabic ; and when A A po pe os reen vitriol, which wi foo he on iy ht for is then to be ftrained t7 black color : 1 to : of fe- i d all vegetable aftringents have the property = WR wv] 1 1¢ cid, ; i th vitriolic acd Gallsan when it is united; either wi allied va og initate thus parating 1ron, id: and the precipitate © fed by 2 or with 24 al of thefe precip Ee from the black. iy of oily matter which they F cerfain ; . {Tes analo- vegetable fublanices. oo ink, fomething pals SHC TC In the ww tation of iron Into age even re- ordp Vor. f other colors. 2s; and om n copperass added fome ib INK | indiked that ink dilittd with i | shin to by hve conf, water has a color a bl INE ¥ ik iss un pave self ered the martial pre cipitate of | INKS (SYMP ATHETIC): Cheniftry furnifhes ack when diluted in a fmall ok gi " many methods of making the inks sailed fy ele 5 beE- | : : i «on. The chief imper- in ti and at lai caufe a very deep blue h Dut this ° inion ue a actually the appearance of a black: | ink or of Prufiian blu Jonelp ond with the properti i hought. this fubje thods is effenti ie. iron precipi the properties of thoug : from 1s eflentially different : pitated in thefe two me- fection of common ’ rom the different’ natures 6 ¢ oo the difference proceed becomes invifible. From experimen with which the iron unites i the two inflammable mat > ’ the decay of inks is chiefly owing inflammable matter whi s itfelf in thefe two cafe [ors | ; th s are the moft perifhable in of inkisin an oily ftat ich unites with iron in the s. The - | quant: ; ateit blacknefs at firfl, blue is not i {4 te; and that in the preparati préparation (whi i ) being infufficient to ingly the a hat ftate. See BLUE Breton). of Pruffian Eo inta ; th i the quantity of galls acids ; Be Precip iron in ink is eafi ae Beco . much h the vitriol 3 ; ficient quanti Ah FeCipuate of Pruffian blue 0 Sluble by all ith ¢ blacknefs of the ink 3 Fe uaLU irit i : ot. 3 : he quantit snk was render ie ink, its oe will dita any other ftron fhe blacker and more WE A diftilled la ai bed 4 ill thus be rendered clear and ppear, and the blackeft hard fpring waters had the fame effefts 3 that white wine pro- acknefs and opacit and tranfparent as w duced a deeper black color than water ; that the color produce fot the ink thus difsolored vn reftored to it bo aiding | by vinegar ee Sie; that proof fpirit ex” aturate a alls cre . J : : bE . aclir non AS LE ied oly 1 cin mensions 3 ic ; : sex art i 2 : Pela os > appearance. Meals this precipitate refi rial preci ropriet of addin {pirit of wme to ink, as 18 frequently di- Thus the bl umes its fo propriety g ip \ difappear and appea black color of ink may be ma: Fiber Tefted, to prevent mouldinefs or freezing 3 that other aftringents, with alten oh r again as often as we Hea b yd fo as te bark were not {0 effetual as galls, color cannot be 3 folkeaeld and fomealkali ; but thi y mixing nor gave fo aced by moft of thefe, ‘any quantit or iced upon the Pruflian blue i han eof excepting 03 that the juice of floes di is fufpende i f an acid to the water in which . By adding La not produce 2 black color with m ut that, never= , its color, fo far from being ica 2 fom blue I Shelets, the. wiih made with it y DECOmeEs ; o be e dau turated folutio , bitort, floe-bark, &¢. a black, the color P _bark, being green 3 artial vitriol 5 b only the mor s e beautiful b ; y that additiom. tartar, of in lemon juice, much inferior tO the ink ma e colof of ink was depraved by adding The col or of Pruffian bl oC ue may be indeed made to appear with martial vitriol 3 that th done with an intention of deftroying any =d to be the caufe at pleafute by one method :. but this method is quicklime, which was hich mi ht be fappof precifely the reverf e of that uféed to produce thofe eff ets up- {uperabundant acid w _ the lofs of the color of ink; that the beft method of preventing ably by adding pieces d on ink. B 3 color is ee alkali with. Pruffian. blue. i acid, the color is reftored y avin this alkali with gis : difference betwixt thef "This ‘conftitutes a very fenfi an. theeffeds of this fupera Inks of all col Sie two martial precipitates y fenfible 1 of iron to engage 1t3 that thi re was confirme! by of the ingredi ors may be made by ufing a ftr id ; an initance the author “of the great durability of the el pam ents ufed for dying, mixed: wi Deion. color of an ink in which pieces of iroa been long immerfed 3 Spd g Spe ic. For example, 2 fron ve a little alum and lafily, that a decoction of Yogwood fed inftead of water erabi as much alum as it can diflc le ecoction of brafil fenfibly 1m roved both the beauty and deepnefs of the black, red eo give it body and fome A ve, and a little gum- without difpofing it to fade. The fame author. nk. (x) ence, forms a beautiful the addition of gum-arabi¢ is not only ufeful, by keeping the > soloing matter] ufpended in the fluid, but alfo by preventing the / - " - . - ’ . (un) As th . ink from 1pre , by which means a greater quantity © it 15 pen #) A h e ovation of records and-other valuab. : INKS 1 colleéted on each fireke © . Sugar, which 1s {ometimes n the goodnefsof the. ink empl R a writings de- A added to inks, was - found ch lefs effeCtual than gums, yed, Dr. Lewis has and to have the inconvenience reventing the drying of the thought 1. ink. The color of ink is found t© be greatly jnjured, bY keeping Fa the - INKS Thefe inks are colorlefs liquors, with which an invifible writing is made, but which becomes very fenfible when we pleafe, by certain treatment appropriated to the particular kind of fympathetic ink employed. As ordinary ink is made black by a mixture of two liquors which are not, or but very little coloured, it may ‘become a fympathetic ink by feveral methods. if green vitriol be diffolved in water, and a little acid be added, to prevent the yellowith martial precipitate, which is always formed when there is not fuperabundant acid, with this folution invifible characters may be written, which may be rendered very black, by being moiftened with aftrong infufion of galls. If the blacknefs of ordinary ink be deftroyed by a fufficient quantity of nitrous acid, the writing made by it will remain invifible, till it be moiftened by liquid fixed alkali. Charaé&ers traced with the acid folution of green vitriol above-mentioned will become of a fine blue color, if they be moiftened with the phlogifticated alkaline liquor ufed in the preparation of Pruflian blue; and charaéters traced with this lait mentioned liquor, which are abfolutely jnvifible, may be rendered of a fine blue color by being moiftened with . a folution of green vitriol. The theory of thefe inks may be feen under the articles INK, and BLUE (PRUssIAN.) the ink in veffels made of copper, or of lead, and probably of any other metal, excepting iron, which the vitriolic acid can diffolve. The foregoing experiments point out for the beft proportions of the ingredients for ink ; one part of green vitriol, one part of powdered logwood, and three parts of powdered galls. The beft menitruum appears to be vinegar or white wine, tho’ for common ufe water is fufficient. If the ink be required fo be of a full color, a quart, or, atmoft, three pints, of liquor may be allowed to three ounces of galls, and to one ounce of each of the other two ingredients. half an ounce of gum may be added to each pint of the liquor. The ingredients may be all put together at once in a convenient veffel, and well fhaken four or five times each day. In ten or twelve days the ink will be fit for ufe, though it will improve by remaining longer on the ingredients : or it may be made more expeditiguily, by adding the gum and vitriol to a deco&tion of galls and logwood in the menitruum. To the ink, after it.has been {eparated from the feculencies, fome coarfe powder of galls, from which the fine duft has been fifted, together with one or two pieces of iren may be added, by which its durabilicy will be fecured, Pure INK S ned by g an impre the charalters W and rendernng / But thisink isnot con d, although weakene d at length deftroys 1t- athetick inks is that ms i acid. The invill be rendered {fenfibly er, liver of {ulphur are | e {olution © Li 1 thetic ribed this fympatheni #1 oh Ss of regulus 4.2 ¥ .cklime 2nd orpiment, wld Se of thefe (ubftances 1s an.’ is an earthy liver ive that they cs ir effect acro ® 1 ble of not appear im o feiss be a ftone wall. “me. We Ag os ] - of bi nitrous qryfe heer Phat the white rach overed we Hg ho ] mal - a ckened on the : arly the vapors 0 pi where phlogiftic vapor liver of fulphur.: . - Wome) 287 Pre readily x i th ma lw nid {olution of liver © The cu s float, partic e by this ink by being alfo be fed as a ion © Jusar 7 ie n application of 2 fotuticn of pears upo hich app F3 in water may (x) A folution of d in fympathetic ink, W The moft modern fympathetic ink, and, at the fame time, one of the moft curious, is that made with a olution of the regulus or calx of cobalt in‘aqua regia. The procefs of this ink has been publifhed in the Memoirs of the Academy of Sciénces by Mr Hellot. . This procefs was very troublefome ; becaufe he direGed ~ that cobalt itfelf fhould be employed, which muft be firfk roafted ; then diffolved ini nitrous acid 5. and, laftly, to the Jolution fome fea-falt muft be added ; and alfo becaufe good cobalt is very fcarce. But this ink may be eafily made. For ~ this purpole, let the zaffye be taken whichis commonly fold by druggifts, from which, by digeftion in aqua regia, may be extracted all that this acid is capable of diflolving : this foluble part of zaffre is the calx of cobalt, which is ufcd for giving a blue color to glafs. This folution is then to be diluted with a little common widter, to prevent it from making too ftrong an impreffion upon paper. Charaéters written with this diluted folution- are invifible when cold, and become of a fine greenifh-blue when heated ; and have this fingular preperty, that after they have been rendered vifible by heat,’ they again difappear when expofed to cold, and may thus be made to appear and dif: alternately, by alternate appli-. cations of heat and cold : but care muft be taken to heat the paper no more than js juft fufficient to make the writing ap- pear; for when it is heated too much, the writing will not again difappear by expofure to cold, This ink may be applied to the drawing of Jandfcapes, in which the earth and trees deftitute of verdure, being drawn with common ink, give a profpect of winter ; and which may be made to aflume the appearance of fpring, by ex- pofure to a gentle heat, which covers the trees with leaves, and the earth with grafs, by rendering vifible thofe parts of the Jandfcapes which are drawd with this fympathetic ink, This idea has been executed upon fire-fcreens by an induf- trioys artift. (y) a re 3d, By liver of fulphur in water, or of the vapors of a liver of fulphur. The juice of lemons and milk have been ufed as fympathetic inks, the writing with which appears: upon the application of heat fuf, ficient to decompofe the oily and mucilaginous parts of thefe liquors. All the fympathetic inks mentioned by authors may be rendered vifible by heat. (7) We may obferve, thata folution of regulus of cobalt, or of zaffre, in {pirit of nitre, acquires a -reddith color by appli¢a- tion of heat. Hence, fome variety of color might be given to : : the 1 2 ON of chemical ; rties © rations, We may any nks with peculiar pie _ The inftru- numereus hey are 210 thereby rendercs . € . a becaufe, Wi ig united s are alo to difumite others is fenle Vv I nitrous OF = j It, W any alkaline falt, W Ip EC A HA IRON : ivid, grey Jes gaye = etal has, nex iron wire, arts; an iro 4 % es inch, being capable out being DOKL: io che light ir Next to tin, 1 when immerfed in Ww art of its weight. Fra iin is fuficiently Very pure if wire Y fine as horfe-hair. called inter the di i fubflancs ” fubftancess oil thout thee 1 hy or even well mi i cfe faline mediate, ch are Lot be otherwife dif: itriolic a€} ] : be difficult to AN : the oreateft tenacity ch isa tenth par 450 pounds with- eft of the metals. e drawn into ] ob ductile { gs of iron are But thefe properti€ e the green {olu- To J] the leaves, the means of wate pantity, oY © fame 3 xtradted. Neuman fubjed ¥ by vi- t bits © and viewe : a of iron, thing bu ‘paper, 4 &ed up oy Sie {cori ons exhibit I RON {ubject to vary much in their degrees, ‘according to the dif. ferent” kinds ‘of ‘iron. T'his Tifercncs proceeds from a ‘quantity, fometimes greater ‘and’ at other times lefs, of an earth contained in iron, which is unttietallic, or ar leaft which is not metallifed, from the great difficulty of fufing i eno perfectly its ore. See Ors of IRON 2nd SMELTING of ORES. “ron by ir hen colle © Iron is the only known ‘fubffance” which is attracted by Ht Eoltifion; an ph appear tO magnets; and capable of becoming itfelf a magnet, fo as to Ly héHns of amICrOITIET2 1 :d heir foluti attract other iron. By this property it may be difcovered in by ase (b) Tolve iron, and 10 : mixtures, where by other’ methods it coud fcarcely be per- pi All the acids difio ; fs. and 2 fufficient ceived, and may be even feparated, ‘when it ‘is only inter- A reicular phenomenice put intoa matr lve its the foluticn pofed ‘betwixt other bodies, ‘and not adherent to them. It . p? 1f filings of WOR acid added to a The vitriolic ‘preferyes this propery; 2lthonsh it bey wi fome E Lantity of Te heat and efferveles PEE; takes flow othér metals. Henkel fa s, in his ‘Pyritolégia, that iron “11 be made With he iron 1n tS e vapors Ww Alsyel with two wi oF copper : i maghctich (4) ” | | will’p hen it ge mable principle : for i; Bore {mell of ron is'a very deftrti&iblé metal.” ts"furface is’ quick : of its If son have no nate converted by the combined 4&ion of air and water jt 4 uit | exhale from this Fe but they arc Oe g or yellow calx, deprived of all its phlogifton. This calx is yolatile falphureos are very i Sa by {i cnly an earth deprived of metallic properties, and which hlogifton, that t ch fenlt at cannot recover thefe properties,’ without being again com- nay be ma Hi as appears from the § ‘bined with its inflammable principle. “The “deftry@ion of : olf b San iron expoied iron expofed to a moift air by ruft;y is” univerfally known, (2) fervad buftion is main “The ruft of iron, and ' the other calxes of this metal, are called faffron of Mars, crocus martis. ‘Se¢' SAFFRON of M ARs. ater alone, without the help of air, feems to be capable of acting upon iron in fome meafure, without depriving it indeed of its inflammable principle ; but it divides and con- fiderably attenuates it ; which feems to thew that this metal contains fome faline parts. See ETHiors MARTIAL, glopuia itrifi d light, and tae Iron is not fufible by the heat of ordinary furnaces ; but it i nd 1m $ ¥pe { a combuition ot is eafily burnt and calcined, by which it is changed into an ; oduced are ‘the effects : rough the air 3 nT fur earthy matter more or lefs reddifh or blackifh, called affrin- i “fufion or vatn their paflage ¥ uy ly the «gent faffron of Mar.. Seethat word. This faffron of Mars is i E> RFE ; Come eat ‘nothing but the proper earth of iron deprived of the greateft effects oe Te min mbuftion, ion, that the part of its phlogifton by calcination. : abi face of t io air, ap = This Sp fone by the Iron heated as much as is poffible, that is, till it be- a to. the parks are De lammable mat- comies of a fhining white color, and juft beginning to fufe, proportt light, " : ow 1 by the collifions : . . nition, Hg : nicatec y {bee 3 has the appearance of a combuftible body, penetrated by a 18 ¢ excited by t ; .ommu ated by Mr. Hawk a vivid and bright flame : and indeed the inflammable princi- So and not mere : re 1lifion are Bo ple of this metal heated to that point, really burns in a fen- i confirmed Bye) La f rks ad deflagrate | ds Ci : ¥ Sieh (a) A much fmaller proportion of iron in an allay of copper | yifible, a ieivers mouth. with that metal, retains its quality of being attralted by mag- an exhaul deflagration ap nets. Gellert aes that this quality is defiroyed by allaying excite thew iron with regulus of antimony, AE Phat i El a fible . I. RON mouth of the matrafs be flopt by a finger duting thirtyor forty feconds, and a lighted candle be brought very near the mouth when it is to be unflopped ; a flame will then immediately appear within the matrafs, and at the fame time a firong ex-= ploiion will happen. This explofion would break the ma- trafs, if the quantity of filings of iyon. was confiderable, for inftance eight or nine ounces, and if the neck of the matrafs was ftraight. ‘This inflammation and this explofion may be frequently repeited, when the: folution is made with fome activity ; and if the matrafs be left unftopt after the explo- fion, and the vapor be kindled, it continues to burn at the mouth of this veflel with a blue tranquil flame, while the folution continues. Se Air (FixABLE INFLAMMABLE), and D Amps. From the folution of iron by vitriolic acid, a vitriolic falt with metallic bafis is formed, which by evaporation and cooling is coagulated into green rhomboidat cryftals. This fale is called martial vitriol, green witrisl, or green copperas. See its properties at the article ViTrioL (MARTIAL); + | Nitrous acid diffolves iron moft actively and violently, This acid cannot eafily be faturated with iron; becaufe when it has diflolved a large quantity of iron, and feems to be fo faturated, that fome of the metal is depofited under form of martial faffron; if more iron be then added, it will be diflolved, while fome of that which was before diffolved will be precipitated, The caufe of this phenomenon is, that the nitrous acid takes from the iron much of its phlogifton during the folu- tion, and alfo that iron has fo much lefs adhefion to nitrous acid, as it is more deprived of phlogifton. This being eftablithed, we may perceive, that er iron containing its due quantity of phlogifton is added to nitrous acid fatg~ rated with a half dephlogifticated iron, this atid, greedy of the inflammable principle, quits the latter metal, and dif- folves the former. ; The vapers of nitrous acid which diffolves iron are always very red, of a2 naufeous fmell, more difagreeable, and appa- rently more volatile, than thofe of the uncombined acid, This obfervation may be applied to all folutions with nitrous” acid of thofe metallic fubftances, which are capable of lofing their inflammable principle. Thefe qualitiesof nitrous acid proceed from the fuperabundant quantity of phlogiften which it imbibes in every folution. Experiments might be made to try whether the vapors which exhale from this fo- lution, and from folutions of feveral other metallic fub-~ 2 ftances ne : ike thofe 5 ion are inflammable, Fak { oh . phlogt ¢ iron 10 vitriolic 3. ne made cautiouflys I€ hi to © de, 4 1 even With no diffolves iron with eafe, and yin : ot take from the Me —— as mitrous act roduce fo s and marin s WD lic bafes, OF 2 th metail ; of. : yw § ron with any | heir color 18 more 5p ndant acid, th ing any de- uperabu ;thout making 4 I reddifh, and 2 hre OF earth called a Hn Yruginous roce Y y ty/ Ga \ {ferences Pp it certain quAnty is depoficed. . ch more acid to keep Jif opt Maes iron 1equiLes lo wri phlogiften- EEA this cases © itis more doprived © t too acid, and. P diffolved, 25 a folutions ofiiroh > heated, they Lafily, WE ated with Watels #0 ity of ochre, WHICH cularly when £7 jately depofite 3.4% long time, if they curbids *3 nok have depofited butina " 2h they would NOt FETE . + are depofited ¥ fey been hosted, Grons. of Mars; Whica ave they require : . Qchres, Or 12 not fo foluble as be again diflolved, fotutions of won. sity of acid OF Er management: much greater qu% us acid, but by pec he acid of © tar particularly BY Ne diffolve ron : Vegetab a6 forms W foluble tartar, TARFARISED) Jo alls are made o ved in which being QUOVEE £aptar, OF tartarifed tinct 2 far; ph Jike other metals, . ? itat abforbent = nts like all others, Preieit= meen 4 is Stabl. (cy This great chomift fs S62 alkalis, confirmed by ther chemifts. | IRON ‘alkalie, different’ phenomena, #¢cording to" the particular fate of the alkali. AORN | ~ If the alkali employed to precipitateliton is as much de- phlogifticated as it can be, the ferruginous precipitate is of the color of ruft. If this alkali contains any fuperabundant phlogifton, a part of this‘phlogifton will be transferred to the iron during its precipitation, and will give it an olive color, more or lefs deep. This precipitate may be eafily and inftantaneoufly rédiffolved by pouring upon it a quantity of acid fufficient to ‘faturate the alkali, and to diffolve the precipitate. This precipitate, when dried with proper pre- caution, (feeETHIOPSMARTIAL) fornisian excellent fafiron of Mars for the ufe of medicine. “Laftly, ‘if an alkali much impregnated, or {till better if faturdted with phlogifton, be added, the precipitate will be of'a blue color, and will form: what is called Pruffian blue. © See BLUR (PRUSSIAN). "Alkalis” act upon iron as upon all other metals, and are: even capable of diffolving it ‘perfetly, when they can feize it fofficicntly divided, as Stahl ‘has difcovered.” For this purpofe a folution” of iron by nitrous’ acid is to be poured into good liquid alkali. Immediately afterwards a red pre- eipitate appears, which, upon agitating the alkaline liquor, inftantly diffolves, and’ communicates to the liquor its color. By this method a confiderable quantity of iron may be dif- folved by an alkali, Wheh this “folution contains much fron, it is called martial alkaline tinéture'sf Stahl. This ope- ration cannot fucceed but in certain circumftances. Thefe circumf{tances will be mentioned-under thearticle TiNcTURE (MARTIAL ALKALINE) of STAHL. When this tincture is well impregnated with iron, a part of the metal is depofited in form of a veryfine yellow brick- eolored faffron of Mars; and at the fame time the tincture lofes much of its color. All the iron may bé quickly fe- parated from it under the fame form, by faturating this alkali with any acid. This ferruginous precipitate is called Stabl’s faffron of Mars. It is rendered fufficiently ‘foluble in acids by the phlogifton transferred to it from the alkali. See SAFFRON of MARs. Iron precipitates metals diffolved in acids; and thefe pre- cipitates have their metallic form and brilliancy, as all me- tallic precipitates, which have been feparated from the acids of their folutions by other metals, have. But iron may be feparated from acids by zinc, and by fome other fubftances.: Sce PrecipiTATION and PRECIPITATE. All vegetable aftringent fubftances, as galls, pomegranate rind, &c. form inks, or black precipitates, with any folutions of iron. SecInk. : Iron accelerate diately after (ORES, iron 15 COP 1OUS, and gether. hcially cl § t i } | 4 FE i 4 H ——— ERY mr t—— eo Ha ano wre Ser I R ON eafth, in thefe different fiates, are from the yellow pale of ruft to a red brown or blackith brown. = Hence we are in- duced to believe that martial earth is never entircly deprived of phlogifton. This is alfo probably the caufe that all thefe preparations of iron are eafily fufceptible of refuming phlo= gifton, and even in the humid way ; for generally metallic calxes refume phlogifton fo much more eafil ys, as they have been lefs perfectly deprived of jt. : Thefe colors retained by calxes of iron render them fit to be ufed in painting, not only with oil; but alfe to tinge glafs. Hence they are fuccefsfully employed for coloring glaffes or artificial precious flones, and for painting different thades of red upon pottery, enamel, and porcelain, Iron may be allayed with all metals excepting lead and mer- cury, with which it has not yet been rendered capable of uniting. Sec ALLAY and TINNING. Laftly, one of the moft interefting properties of iron is, that it is capable of being combined either by fufion or by cementation with a more abundant quantity of phlogiiton ; of being converted thereby into a more perfect iron called Jleel, which’ is capable of “acquiring, by fudden cooling or tempering, a very great hardnefs, which renders it very uieful for numberlefs neceflary pupofes. See STEEL. The affinities of iron are, according to Mr. Geoffroy’s Table, in the following order : Regulus of antimony, filver, copper, and lead. Thefe three laft are placed {o as to mark an equal degree of affinity withiron. But we muft oblerve, that lead ought not to have been placed there, becauf= it has no affinity with iron : but as iron united with filver may be inftantly feparated from the filver by addition of lead, which unites with the filver, and obliges the iron to float upon the furface of this new mixture; Mr. Geoftroy feems to have meant to have fhewn this effe& in this column of his Table. of Affinities, which however is not very accurate : for this experiment only fhews, that fiver quits iron to unite with - lead. Mr. Gellert’s Table of Solutions gives for the affinities of iron, gold, filver, and copper. Lead and mercury might be placed at the bottom of the column, where fubftances are mentioned which cannot be united with that which is placed at the head of the column. (d) The (2) Iron like other metals is faid to.confilt of earth, phlo- gifton, and a metallic or mercurial principle. 'T'eichmeyer re- lates an experiment by which the exiftence of the mercurial prin- ciple is pretended to be proved. He fays, that by diftilling iron filings, {RON and fo RUMErous, are fo well iH fhall only iron enumerated. . { the Itis, aS it we all. 1. « exiftence of them medies, the “his 18 hes alfo very ERC . 3 re wel ctablihed BY Pay be taker Cc sh ie not V1 1. Rid in fn metal or fed it be well div ided 1 ah . acid, jtignes, n when united W It never produces . danger. ity an > wisodt SON (uicable quantity : hen app « caufed by its tonic . 3 e % . of iron 1 ioht and gen jeinal VIrEE duces a flight S00 oe qualities, & of which 1s, tO eon o encreaie hich it acts, and © in effels of and the velic fines proceed $3 fuch ar organs jth diarrhe?, difeafes which pros ccompani poch e tions 2 Ha | ¢ ical, hy cokes, Sos many hyfietica Aypoet a oi fecions, interm! cholic @ 8 alfo been always osha 3 a&kitioners as a fe z on and feve ood ifts cl oe i ualitie thening quai : fren the cafes i wh 0 . . 4 aperitive eiecls “Ty EE sion 1 chloroits, fe of A ne the fame bf difeafes 0 hn . 1 inds of } in fome ki 1 to ” fed during 3 year . ar to the air, flings, which h as expofed another yee § £ the veflel, 30 gricurated, a0 hich ftuc eC k tothe n ots of the a . and the ous of 18ON 5 The ir, them the a he he jrom 07ESy pou Jn SMELTING Aoilrgieal Hip) of Irons Jee and STEEL: mr a mr —— ry — Pe —— SIS + ee EE eet mmm oe 4 BE a Ea a {1 1 JUICES The excrements: of perfons ufing martial. remedies are blackith, or even black, which proceeds from a mixture of + this metal diffolved with the aliments. This proves, that if iron penetrates farther than the prima viz, it muft be in very {mall quantity, fince the greateft part of it is ejected with the excrements: ; As the principal effe@ of iron is to tenfion, and the {pring of the folid effet cannot be continued without a continuance of the martial remedy for fome confiderable time ; otherwife onl ya tranfient relief would be given, and the difeafe would foon recur. i ISINGLASS. (e) JUICES of PLANTS. The are exprefled to obtain their effentia] falts, and for feveral medicinal purpofes, with intention either to be ufed without further preparation, of to be made into {yrups and ex- tralls. change the tone, the parts of the body, this juices of fevera] plants (e) Isincrass, Iethyoeolla, Sfo-glus. reneouily faid, that it is Prepared by boiling the finewy parts of a filh in water. ‘This preparation would make glue, but not ifin- glafs. No artificial heat js employed, nor is the matter diflolved, for thereby the fibrous texture would be deftroyed, which is an effential charaleriftic of ifinglafs. Ifinglafs is nothing more than certain membrano us parts of fithes divefted of their native muco- » tolled and twifted into the forms above mentioned, and dried in the open air. The founds or air-bladders of frefh water fith are preferred for this purpofe, as being the moft tranfparent, flexible, delicate {fubftances. Thefe conftitute the fineft forts of tinglafs. Thofe forts called book and ordinary ftaple are made of the inteftines, and probably the peritonzam of the fifh. The Beluga yields the greatelt quantity as being the largeft, and moit plentiful fith in the Mufcovy rivers ; but the founds of all freth- water fith yield more or lefs fine ifinglafs. Mr, Jackfon pro- pofes that it fhould be made of the founds of cod and ling See An Account of the Manner of making Ifinglafs, by Humphrey J:ckfon, Efq; Phil. Tranf, vol. LXI11. fram which the ataove is extracted, Ifinglafs is total {pirit of wine. From eight ounces of by diftillation, four ounces and two dra an ounce of concrete volat reumatic oil, half It is generally, but er- ly foluble in water, but not at all in reétified ifinglafs were obtained, ms of urinous {pirit, half ile falt, an ounce and a half of empy- a fcruple of fixed falt, and nine diams of earth. Minglafs is employed as a glue for mary purpofes, and for fining wires. Neuman. : The wounding the pla UICES - 3 f extra&ting fhefu juss ry i 4 rose mortar, and then DY nt in liquors, s ’ dd and green Thus is a et, as we fhall foon na seneral meth : 5. it ine 2 pr ally requires tO ith equal eafe. which g re not extracted - twice, that obferve. f all plants 2 tain fo little } fe The jutces 0 when frefh, con ounded, otherwi Some plants, Oe ad while they are Pexpreffion. Othes water muft be 2 would be obtaine Lity of juice, furni {carcely oN Jee a copfiistnple Tr becaufe ey ad s whic all quant! juice 10 by expefion but 8 foal GUE, coger dhe gues © vif tain ato Wis Gow: Water muft a that it can! hE chanical . 1r uice. - es b a me lants to diigia fb ied from vegetabl J The juices ir principles, . of their prinl ng, one ¢ inciples 0 . erly fpeakl mate pri but fathet h es foluble in water trou principle, 7 1 a . os t e . e il- ts whic ucilage, 11 which ar plan ‘ r, the muc ) es; all d matter, {ubftances ; Befides extractive I ccharine : e plants. 11 the {aline and fa he vegetation of the p + of the refi- P in the water of the Veg tains fome par hich in five Tihs s, the juice Son ing matter, which J! all thefe matter id the green color A ). Thefe two CC na <7 3 ter- fits Ju vegetables is of 2 He . water, are only ? are 1 Vv * 1 u . : wl vic @“ almoit a t being 10 inciples V latter fubftances, 10 arts of the other us its tranfpa- fed between the P nd confequently ditu! eertaibde- ai in the juice, an together in t be diffolved in the) verthelefs adhere tog that they canno rency. rear in moft juices, 0 - orec, an | 4 ified, fome pre- When therefore muft be ufed by which ¢ Toi phon ig a which are 2) ; Suv ant be facilitated. fi oT clarine n y 7) RE laginous, are 1p of moft apt uorbull Pe merely heat, ‘The juices inles, may be difpole Con {aline volatile DE tin water ; and os a o erin while they are th tained 1n C feem to bles does not 24 Bue of wages accidentally L) The coloring fubiare® but only to sdhore HL {een i ny matters of Pl rth of alum the piec it dr {e fo as to form with Sa an of fopestd fog ne it 1s not {oluble eine i itates called lakes, 1 of wine. i DYEING. a Vol. JUPITER bath, their faline volati A A tile part, in which : TI | is chy ct, ma ti be prs Ferment effeCtua method of spot a nel] ae fo feepiible of it ; for all Bee Which eo ; Sy fpontaneoufly after fermentation. But ements od or uid to clarify juices, becaufe man or il ie wl perieds tin, and on eels. of moft of them are injured by that pro- The method of clarificati di rification moft generall , Sipenitbly recelliy Sor Sow Is es 8% by boiling with the white of an . am Re water y one has the property of rs boiling At Sang with mucilage, does cordingly: their m 1s o the juice of plants, unite with and c 1 yr hele oy age, and feparates it from the juice in f ge a et ogether with the greateft part of the refi Sra of sem Fano which difturb its tranfparenc Fp 2nd li hoe fogs matters which may AA he os any cad oo olny with the whites of eggs, are no Be uci 2 - Sve See F si Ww may eably be feparated by e juices, efpecially bef . 1 ally before they are clarifi { Sime all the ome principles as the plant tlelf hy Yin pe per lon y which they are extracted no Tecra Ge In pr by mpi 1 a fn oo e plant. he principles eh jujepare only {eparated from the ters Auk in he Tn which compofe the folid aad i a ER ee Da Thefe juices, when well prepared ry Ene hor res y the fame medicinal qualities as the ] ve Som te they are obtained. They muft evident] P ri as hn nature and proportions of A isl 1 ey are impre nated ® plants from which they are ee differ ae much as the in thofe refpects. rom each other IVORY frac © : . By thi A. add ro Tre y this name the old chemifts diftinguifhed (g) See the article BLack. ALL (h) 1 WW KAOLIN. i) KARAT. Thi parts which are fuppofed t or purity of which 1 i e of purity, the whole mafs of it, to be divided into 24 parts, Hence, when g0 called go J o the pioportiorial {s of gold, the value ‘When therefore old is confi be its real weight, is fuppofed and thefe parts are called karats. 1d is entirely pure and without alloy, itis 1d of 24 karats. £ it contains 77 part of alloy, old of 23 karats, becaufe in fuch 2 mafs 33 are If the mafs of gold be 2 or rz © f 22 karats, and fo on. For greater fubdivided into 32 Parts, _fecond parts of 2- it is called g old, and 72% is alloy. alloy, itis called gold © precifion, the karat is {fuppofed to be which have no other name than the thirty karat (k). See EssaY of the V ALUE of GoLD and of SILVER. hb) Karrisa maritime plant, from the afhes of which a con- fiderable quantity of mineral fixed alkali is obtained by lixivia- tion, See ALI , MINERAL). Henkel informs us, that by boiling and by evaporating the de- cotion, he obtai ntity of fea-falt. is the name of an earth which is ufed as one of (i) Kaocrin 1 redients of the oriental porcelain. Some of this earth 1 ¢ the two ing; was brought from China, and examined by Mr. Reaumur. found that it was perfeétly unfufible by fire. He believed that it was a talky earth; but the author of this Diétionary obferves, that it is more probably an argillaceous ear 1 a tenacious pafte with the other ingredient ¢ has no tenacity. Mr. Bomare fays, that by analyfing {ome Chinele kaolin, he foun d earth confifting of clay, to which it owed its tenacity ; th, which gave1it a mealy appearance ; of fparkling particles of mica, and © {mall gravel or particles of quartz cryftals. He fays, that he has found a fimilar earth upon 2 fratum of granite, and conjettures that it may bea decompofed granite. This conje&ure is the more probable, as kaolins are frequently found in the neighbourhood of ' Granites. See PORCELAIN: (4) The karat, or carat, in England, is divided into four parts only, called grains, and in Germany into twelve parts. Standar old in England 1s gold of twenty-two carats, that is, it con- tains 1; part of alloy, which is generally a mixture of copper an filver ; as the whole proportion of the copper would make the hole proportion of the filver gold too high-colored, and the w would make 1t too pale. G2 ~The | ! | i i {| y : | | — _— A —— a te SS KERMES The word karat, when applied to diamonds, fignifies a real weight of four grains. KERMES. (/) KERMES MINERAL. Kermes mineral, fo called from its color, which refembles that of vegetable kermes, is one of the moft important antimonial preparations, both with regard to its chemical phenomena and to its medicinal ufes. The ufe of kermes mineral was not eftablithed in medi- cine before the beginning of this century. Some chenfifts, indeed, amongft others Glauber and Lemeri, had before that time mentioned in their works feveral preparations of anti- mony which approach more or lefs to kermes ; but thefe preparations being little known, were con founded with many others which are entirely neglected, although much praifed by their authors. The fame of kermes was occafioned by Friar Simon, apo- thecary to the Chartreux Friars. This friar received this preparation from a furgeon called La Ligerie, who had pro- cured it from a German apothecary who had been a fcholar of the famous Glauber. Friar Simon, from the commenda- tions given to this new remedy by La Ligerie, adminiftered it to a Chartreux Friar who was dangeroufly ill of a violent peripneumony, by which the Friar was {uddenly, and as it had been miraculoufly, cured. From that time’ the Friar apothecary publifhed the virtue of his remedy. Several other remarkable cures were performed by means of kermes. The public believed in its medicinal ‘qualities, and called it Powder of Chartreux ; becaufe it was prepared only in the apothecary’s hop belonging to thefe monks, The reputa- tion of kermes extended itfelf more and more; till at length the Duke of Orleans, then Regent of France, procured the publication of the procefs by La Ligerie. This is the hiftory of kermes, as it is related by Mr. Baron, in his edition of Lemeri’s Chemiftry. Although the procefs for making this preparation be very accurately defcribed in this and other books, we fhall treat of it in de- tail, becaufe it is a matter of much importance, (7) Kermes are excrefcences formed by infefts on the branches and leaves of the fcarlet oak. They communicate a red color to water or to fpirit of wine, Woollen cloth, previouily dipped in a {olution of alum and of tartar in water, receives from a deco&@ion of kermes a more durable, but lefs vivid, {carlet dye ther that ufually procured from cochineal, together with a {olution Of tin. The KERMES ioeri {ifts ublifhed by La Ligerie, conbii The pro re pulverifed crude mney n th boiling, ; ht of the liquor of nitre Ag 2 tas gh ht of pure pi at he Fk ey an 2 trated, W | ne liquor 1s tO be decanted and filtrated, i ao d brick color ain becomes clear b oe Jipedun re I : 9 g of a red fediment, me the fame quantity of water be thrice repeated, d a fourth part lefs of the : timony, an 7 . gw 4) i Cel The ’feveral frinents fom Ree liquor OF, es to be added together, wafhed wi Lp three boilings are fe; and the kerm ires no tai water, till the wats! dr that aqua VIZ all then to be dried. La Tiga : irels that nd the kenmes ured up be once or twice pO ied acain. . i Hg proceed to explo i ] reparaticil. . the phenomena o) i A 3 of regulus nf anfimony Crade Ant er, wil pis i roi ‘common iu iwith w thi con 1 lic minerals. d alka Foi 1 with in almoft all me although 1t 15 diluted Vv the crude antimony 1s boiled, 2 f the antimony hur © much water, acts upon OE 2 this compound is s with it liver of fu ; ar it ji To £ all metallic maiters, it diffolves a cert q ins a folvent oi 8 1 his operation the i f antimony. : iL of fixed alkall, of fulphur, and © ulus of -antimony. Of thefe three foes, De frgs alkali only is foluble in i, and Re ny re pended in : a : ftance by which the fulp i bol. 1 the ali becomes [he tl bv this operation, and by a ’ on he ay of regulus, and efpecially of & on i oy fufpended in cold 3 the ANEW : which is clear, limp, 2 Togs leit cools. This comes turbid, and depofites 2 fediment while? ar Le certain {alts, may compound, therefore, Het hot than by cold water, an ed in larger quantity Dy. hh of it is therefore depofited by ging HM, Further, while the kermes is precipitating, Ta Fur! : 3 liver of fulphur, which 1s diffolved by gt he : r, may be divided into two parts ; one oy ih oi Es Jw being overcharged A Si, particularly with the Pigkls, contal n the nature of kermes, and which KERMES which it draws al . other ys. a ong with it during it . Sess party as I6 confine 2 Sing He depopicn, The tity of. alkali, .. old liquor, by means of 9 ains dif demon Baal 5 All thefe propofitions id fa larger quan- Fir, NS he following obfervations e explained and formed all its fed: e decoction of kermes is cold it be heated ments if, without adding an oh and has armen dhe folio boll, 3s egal TS DA to i and by cold is a i the liquor beco oles Bn as before. ered turbid clear, and ofS, is the kermes may p04 depotites fediment ~ Second] ; — often as we pleafe. § 1 preepitaie folves its > lighting kermes in aqua regia, which di fo acids of aqua a the fulphur is a 3 ylvius with the alkali orm a nitre and a febrifugal fal e quantity of kermes b ali of the kermes; and eS alt of deftroyed its ful es be melted with black fl a certain hur b i ck flux, after having may be obtained 1 by roan atrue regulus of as e . rh and i SXDempnly) which were made by Mr. GC Academy in the which is found in Memors ly soffor Ee a eis 1 an alkali, and of e preience of fulphu From Mr. G regulus of antimony, in 5 r, of fixed kermes Lo Goats experiments i fi compound. grains of alkalis out 16 or 17 grains of Ti Ry grauns of fulph ine falt, and 40 or ; » 13 0r 14 : So 4 41 grains of common , ar y> by repeatin “qs antimo g the boiling of the li by i now 2 more kermes will be © Sau Yeon the a great Wii a rft ; and this experiment ma Wi time 78 times me Mr. Geoffroy fays, that Sareea] to fipply a ii other addition than that of pcan it me a a evaporation ; = a, ‘his experiment ity of kermes was formed b : . proves, that th eal; y cooling, mony int ? e alkali tr : >" or ee ao EN ’ Y Sn Grrgingitielf he ful take with i cipitation the ke , > ; DW & ht a very fall a Ses at retain and che Eatmed , if any acid be poured upon the li iy : tirely mo en formed, and pis A ge liquor be which this liquor is a y cooling, Myr. Beaumé has obfer i il ment, is tae of eo red wig and that a foo oy elfe th ellow reddifh colo rl, di- ele than golden fulphur of antimony ; a han : an- timony proportions, KERMES and fulphur mixed togethers b and with different ftrength re found in the cry ut in very different s of union, from hich they 2 de antimony. 9¢¢ “thofe in whic SuLPHUR (GOLDEN) of ANTIMONY. ; ipitati 1 or a neutral {alt is left, After th which is acide F which th : of antimonia i kermes ion of alkali 3 {o that it can which it is united, 1s pre It} he precipitating formed by rom this €¥ the liquor from quantity by containing a muc | keep diffolved the regulus and fulphur with when the liquor is cold. + 1 or the manner in which han an antimoni redominates, 2 luble in water article we may paration, more alk and before it ali than after it kermes has be re-diffolved ; but as 1e kermes wh which is moft alkaline, tl that it 1s nO longer tains fo litt all the qualitie al antimo kermes, © happens when ¢ quantity of alkaline 1 ted liver of i ulus and ful- fulphur refults from it; © s than it phur; that 1S, containi can keep diffolyed in cold water If anyo be boiled in water, matter analogous tO pofited by cooling. This happens, for inftance, of the regulus of antimony, and inan operation Mr. Geoftroy to abridge the procefs for making kermes by fu- fion. To make kermes by fufion, Mr. Geoffroy fufes two parts of antimony with one part of alkaline falt ; he powders this matter while yet hot, and keeps it during two hours 11 boiling water 5 he then filtrates it, and receives the liquor into more boiling i when 1t cools, about fix gros of kermes is depofited, f antimony when an ounce o has been ufed, This method 0 es is MucC 4 f making kerm more KERMES more expeditious, but lefs perfect; for, as the author con- fefles, the kermes produced is not fo fine and foft as that made in the ordinary method. Mr. Lemeri the elder mentionsalfo, inhis T'reatife concern- Ing Antimony, an operation from which his fon pretends that kermes may be obtained. "This operation confiftsin di gefting, and afterwards boiling, powdered crude antimony in a very pure liquor of fixed nitre. This liquor, if it be in fufficient quantity, is capable of diffolving quickly and entirely pow- dered crude antimony, and we cannot doubt but that by cooling a confiderable quantity of a fubftance very analogous to kermes will be produced.” Neverthelefs, none of thefe fhort methods of making kermes is directed by difpenfatories, or by the beft books for defcribing the preparations of che- mical remedies ; and we muft allow, that this is done pru- dently ; for, befides that all thefe kinds of kermes may be Tufpected to be lefs fine, or more charged with reguline parts than that which is prepared by the ordinary procefs ; when the conftant obfervation of medical practi oners has afcer- tained the effects of a compound remedy; fuch a remedy ought to be confidered as it were confecrated by a refpecable kind of empiricifin, againft which the fineft theory and moft {pecious reafonings ought not to avail. The leaft reforma- tion or innovation ought then to be confidered as a blameable rafhnefs, particularly when a remedy of fuch importance is concerned. Kermes is ufed in medicine only, and from it fingularly excellent effets may be produced, when adminiftered by able phyficians. In kermes are united the exciting and eva- cuant virtues of the emetic preparations of antimony," with the tonic, dividing, aperitive, and refolving properties of the liver of fulphur ; that is to fay, that it is capable of anfwering two principal indications in the treatment of many acute and chronic difeafes. Properly managed, it may become an emetic, purgative, a diuretic, a fudorific, or an expectorant, as is required, and it is always attenuat- ing and refolving. When feven or eight grains are taken at once, it chiefly alts upon the prime vie generally as an emetic and as a purgative. © A dofe of three or four grains i$ feldom emetic, and more frequently purgative. When taken in thefe quantities as an evacuant, a little of it pafles alfo into the viz fecundz & tertiz. When it is adminiftered in fmaller dofes, it paffes almoft entirely into the latteal, blood, and lymphatic veflels. In thefe it occa- fions fuch fpafms and ofcillations as it does in the prima viz ; iQ {o that 1t €° cular] a the dofe 2 fition in tho and obftru he difpo- difeafe, and tof fh ue gs tt fingularly good effects atient. , d from fullnefs of the patient CP which procee eafas of the breate'V fe difeafes © ni} inl miniftered Am ehicle; or incorporat sto little One precautiofly © = ith aci that is, not to] pact an iq kermes. afk a8 KEIRA ie. atient \ b ioined with 1t, if the pas : ught to b¢ difpofition nme ViE, Of > he alkali by W d by which or of fulphur, anc oJ = d pnd hur of antimony, they a den fulphur © ilar to the golden S entirely nm hi h are verv € (- ingly ¥ tes of which are velJ o cordingly, Atimony, the properties SULPHU (GoroEx) of fulphur o oft of kermes. See SUL ” ought to prefer ferent fon In fome cafes, cen wathed, gh N VN ON $ 5 . J Ash: afhed kermaes tof ; h the kinds, aS Mr the unWalll® caries ought © KEP P00 op emiftry. therefore apo 5 5 1 edition of Lem 1 ohemifts divide a1 Baron propoles MIS Moft naturalifts oe hey call king- akg: s into three ged" Shai Stl and the anima al bodie ; ble, ER a ate hg wins oms. Tv: nfidera- : . on tis CO ; kingdoms. nd firft divifion 18 founded | roduced, which This great a 1 r vegetable whic X P 1 and which : hat any plant of VEG=" . ntains 2 feed, . tion, t BE is orga Jifed, which co 9 diftin& ond dif- 1 ing ve A og orows, WHich : ms to be 5 sft oblerve o : i fecms : : ;e at MC es its like, hich we ¢ : C. roduces 1t . metal, in Wh roanifa- tone or a1 ’ ota truce Oly gions fons DE tt of parts, Ca it is capable © a ¢ ud xr WW ~ . only a regu 4; h contains no feed BY W of this divifion 15 : ¢ - 1 nls ~ gion, and whic 4 another foundation lant, by fenfa- duétion ; and « : from 2 {imple plants ; re imal differs no lefs tro ne power of voluntary that sn arti fe of its fenfes, and Byte De ities do not be- tion, by the u h Teles while theic Gg! ,€ tion which 1t policies, ly vegetable. n moti . which 18 mere Y 2 ain&Give fome phi- long to any WAG VT, re marks fo Qiflin Arve f natural . . or i 4 iC 3 - 11as ut notwithftandiy is divifion into gfe, ie na- that U at by oDI€ Be. lofophers al "They affirm, that oY Jultions bodies 1s only i : er proauet av erceive ain + ana that ture attentively, Ne x 2 uninterrupted chain 3 vinced that (ted tog : {t be convince pe Soneftel ot eral beings, WC muit b any by furveying the fever 5 # . according so oe r in cor- 1 n&us’s, in ys oe be a i Kermes may i ny V s, 10 a (uitable remedies. we certain -al, the veget A a ———— — Cs ct. C—O = KINGDOMS any one being differs very little from fome other two, betwixt which it feems to be placed ; fo that we may defcend from the moft perfeft animal to the rudeft mineral by infenfible degrees, and without finding any interval from which a di- vifion might be made. This idea is certainly great, fublime, and not improba- + ble; for if we compare a polypus with the Jenfitive plant, or a Zichen with a beautiful ore of ramified native filver, we fhall be inclined to confider this opinion as conformable to the plan of nature, ; : The opinions of naturalifts are therefore divided upon this fubject, and each opinion feems to be founded on obferva- tions, analogies, and reafonings more or lefs conclufive. But as the difcuffion-of this matter is foreign to our fubjeét, - we fhall not enter into a more particular detail, but we fhall confider natural bodies only in a chemical view; that is to fay, relatively to the feveral principles which we obtain in the analyfis of thofe bodies. We proceed therefore to thew what experiments have taught us on this fubject. In the de- compofition of all beings truly living, organifed, and con- taining within themfelves a feed by which they may be reproduced, fuch as vegetables and animals, we always obtain an inflammable, fat, or oily fubftance ; and on the contrary, we do not find the fmalleft trace of this principle in any fubftance purely mineral, not even in fulphur, which is the moft inflammable of all thefe fubftances. On the other fide, if we carefully examine and compare with each other the analogous principles obtained from the three kingdoms ; fuch as the faline fubftances obtained in the analyfis of ani- mals, vegetables, and minerals; we fhall eafily perceive that all the faline matter which comes from the vegetable or ani- mal kingdoms is altered by oil, while al] the faline matter Which comes from the mineral kingdom is entirely free from oil. We ought to obferve here, that becaufe any matter is found in one or more individuals of any kingdom, we muft not therefore conclude, that it belongs to the kingdom of fuchin- dividuals ; for we may be convinced, from a flight obfervation of nature, that by a thoufand combinations, and particular circumftances, fubftances of quite different clafles or king- doms are daily found mixed and confounded together. Thus, for example, within the earth, and even at great depths, that is, in the region appropriated to minerals, fometimes fubftances are found evidently oily, fuch as all bitumens : but we at the fame time can prove, and all the obfervations of natural AS BY pele oily fubflunces arc 17 ) hiftory Proves © rth, and that £3 4 ally within th adies which have been f thofe grea rface ¢ he wi animals, 's {alt, ound 3 : :« becaufe they ‘ving bodics, ole Hv . ich have been red am of e nu : hey ought not tob at not only the and that t this is, that not The proof of form in animals an es. bs f thefe mineral falts 15 uch falts is con- 5 ta nd healthy, put alfo, that no" * 1° ually firong2 c ypiains ns AEA hich thefe falts hav fpecies 0 Soup : : lace, we oblerve, ft nd animals; ® 1x the fecond P ipl es of vegetables 2! y into their n . the proximate,P. ~ es which en in thofe of the ompofition, or further decompofitions, referve their aniy ot outrefaction ER = By ; i to erations, NO ; Joe 4 ble bodies ar€ forme : y 221 ro il may itfelf be ubftances 10 that iftingul which they can Se le, of V¢ and = i OR : {ufficient calginatiov : oat en fimilar to ter, earths foun as Minera a par formerly 2 P : if veuctable acids we ble, he . = poll fe po ii charadteriftic proper wos der n jeids e conclude, that ip in 3 Bal view, We ought 0 jn ac | y exift in that 18, jatel ter immediate by ties atural bodies to two great clafles. KINGDOMS clafles Th o> e frft . ganifed, and the clafs is of fubftances inanimate, plicity which is |Prineiples of which have imate, unor- thor Catt contal ential to them : thefe ar a degree of fim- diftinQly LEA oh thofe bodies which Fo sale, The which 1s no > ut which alf . y ave been ; where . 0 contain a. part of animate ® found in fubftances Lt 7 oily matter, the other principle ies, and which, by combinin ROL made thefc principles B s of thefe animate bodies mang with all fimplicity. This on thofe of minerals b if : inguifhes mals. We ought Seong clafs contains Veet] s degree of vegetable and iat to remark, that the oil igs and ani- fermentation, pr ubftances renders them fi ontained in means take rey fo called, which ca ufceptible of FERMENTATION ny mineral. See ean by any We fhall OW iLs, PUTREFACTION od hen principles gw proceed to examine, if, b co ARTHS, thofe obtained in th dl Be Serompolin, pete mparing the fome effential cha © Steompaniion of Sook Yogrbins with be chemically diftin er by which thefe two o re can find feen that«both of iaguifhcdyein the fame re oms may From experiments em may be diftinguifhed er we have vegetables orm Se indeed learn, that the Th pera: that in gene ently enough f nciples of ral the faline Be igh from thofe of ani and arc ig aline principle | animals 3 + nsformable 1 ples of the forme id incineration ; in great meafure into | ner are acid . while th Sh re into fixed alkali > alkalis ? e principl alkali b , or eafil nciples of thel 4 Bech Birthet ak changeable into thefe ; 5 igtar are volatile iat oils truly io a i putrefaction than EYogsiesles ere le oils : es chat piled ars 1 ' = and are i acter differe Ys .difpofed to be Tn general more attenuated nt from vegeta- the fame time enuated and volatilifed. Ba at leaft more and decifive } one, that thefe differences we muft, at mineral kingdom fofe betwixt thefe two kin dor pot Siear either in animals or we do not find any Wi and de found In the fe in vegetables, which is not prineipls, as much volatile a fome plants, chiefly the 2 fo to be difpofition to wy 1, » little fixed alkali 2 fugitarms thence we trify, are found as in ani ’ s much ! conclud et ! as in animal mat bodies dike e, that if thefe ty atters ; and ier chemicall efe two great clafles of Er ceeds only fr ally from each othe lafles of natural os om the quantiti other, this differenc principles and quantities or proportio nce pro- : ; properties ns of their fe and peculia prop , and not fr , veral ¢ r : om an ns vegétable and oe 3 it fimilar to the om amy ung diftinét by containing al FanAiness differ from ay hich bath oll, and pofielinga A ar ; a ity, Befides, LABOR ATORY e degrees of the chemical differences betwixt thefe cat clafles of natural bodies are found to be the {ame, er manner We confider them OF compare them to~ AL). As chemiftry is cperiments, W¢ cannot *(s a certain degree of aking f fall verify moft 0 fundamental operations, and alfo fuch as reafon- +. and the fpirit of inquiry, never fail to fuggeft and fuitable calents lead them tO this mental philofophy- cfides, when 2 and operates, ne muft perceives ft common operations, 2 great variety of {mall ceflarily be known, but which are not mentione books or in Memoirs, becaufe they are £00 NUMErous, and would appear too minute. Laftly, how many qualities are in the feveral chemical agents,. of which no juft notion can be given by writing, and which are per- fedtly well known as foon a8 they have been once made to firike our {enfes ? Whoever, therefore, would become 2 chemift, muft indif- penfably have a laboratory furnithed with the moft neceflary \nftruments for the practice of this fcience; and we therefore think proper : on what thefe are. Our intention 18 not to fpeak f stories defigned for ope- rations in th thofe which are appropriated to {ome particular part 0 for example, tO eflays, enamels, &C but of the kind of laboratory which is proper for a philofophical chemift, to make occafionally, In {mall, any chemical operation whatever, Such 2 laboratory ne- cellarily occafions certain expences, but not fo much as is generally believed, when the operator knows how to manage his utentils, and to employ only the proper quantity of the ach experiments a effential part of experi - {elf obferves, d either 10 nor of f chemiflry ; as, mineral containing d cobalt, mi- of a vitreous fifting © m) Kuprer-NICKEL is a reddifh yellow the femi-metal called nickel, together with iron an neralifed by arfenicand by fulphur. It is fometimes texture, fometimes fine-grained, and fometimes con fcaly particles. See N1CKEL. : feveral LABORATORY feveral fubftances upon which he operates ; and laftly, when he chafis the leaft expenfive methods of attaining his pur< pofes. | Many people think, that a laboratory level with the ground is moft convenient, for the fake of water, pounding, wathing, &c. Itcertainly has thefe advantages; but it is alfo fubject to a very great iriconvenience from moifture. Conftant moifture, tho’ not very confiderable and fenfible in many refpects, is a very great inconvenience in a chemi= cal laboratory. In fucha place, moft faline matters become moift in time; the infcriptions fall off, or are effaced ; the bellows rot; the metals ruft; the furnaces moulder, and every thing almoft fpoils. A laboratory therefore is more advantageoufly placed above than below the ground, that it may be as dry as is pofiible. The air muft have free accefs to it; and it muft even be fo conftruted, that, by means of two or more oppofite openings, a current of air may be ad- mitted to carry off any noxious vapors or duit. In the laboratory a chimney ought to be conftruted, fo high that a perfon may eafily ftand under it, and as extenfive as is poffible ; that is, from one wall toanother. The tube of this chimney ought to be as high as is poflible, and fuf- ficiently contracted to make a good draught. As charcoal only is burnt under this chimney, no foot is colle&ted in it 3 and therefore it need not be fo wide as to allow a chimney- fweeper to pafs up into it. Under this chimney may be conftruéted fome brick furna- ces, particularly a melting furnace, a furnace for diftilling withan alembic, and one or two ovens like thofe in kitchens. The reft of the fpace ought to be filled up with ftands of different heights, from a foot to a foot and a half, on which portable furnaces of all kinds are to be placed. Thefe fur naces are the moft convenient, from the facility of difpofing them at pleafure ; and they are the only furnaces which are neceflary in a fmall laboratory. A double bellows of mode- rate fize muft alfo be placed as commodioufly under the chimney, or as near as the place will allow. Thefe bellows are fometimes mounted in a portable frame ; which is fuf- ficiently convenient when the bellows is not more than eighteen or twenty inches. Thefe bellows ought to have a pipe directed towards the hearth where the forge is to be placed. The neceflary furnaces are, the fimple furnace, for dif- tilling with a copper alembic; a lamp furnace ; two rever- beratory furnaces, of different fizes, for diftilling with retorts ; an an al $2088 TORY e. and a forge elting furnace; an es I 9 hele furnaces I A the enumerabiic wd ji PSee alfo PLATES ords FORGE a” nvenient height, Under the chilEe) ek and fidewalls; upon W hook driven into : raight, Ww O iven Int ! : ans ; tongs j 10 f s ar {mall {hovels iron pa S53 her are to be hung and oth and circ p ; ibles. ooked d circular incers; P ng the crucibl cr ’ agi tenfils for difpofing the fuel and matey be faftened {helves u to : laboratory OUg A lves ma be To the walls of $s and heights; OF thes pele. a 30 of different yea ks ‘The fhelves are to oo to be in as great fufpended by hoo ¢ operations, and oug here many X= d the products oO P in a laboratory w tves an flible. ¢ have to0 many fhe , ain t place for 2 fone or jeadely er it a ; is 2 A of the Jaborstory 2 oh the water to contain wa be placed with pipe veflels are always a ciftern ought (charge itfelf. As _brufhes ought oured into 1t May diicha’s ths and bottle-brut ; n, clo ¢ cleaned under Sit fo faffened in the walls near 1 is to placed, to be pe ng en Wi laboratory 2 A for gpewas In the mi are to be made. tions ; ina Words on wih mixtures ar¢ tions, {mall i eS alamp: tions, ing t excepting ose whatever docs 70 of the laboratory are to be Pp one of which is ta fupport 2 . $i Le blocks of wood upon jess 3 fupport 2 middle-fize 1 mortar, :ddle-fized iron i midd her hard-ftone fs ik es of differe ve to er vil. Near the i il are hung 2 hammer, the any 11 utenfils, and finenefs and De es, {heers, and other {ma incers, 8 ought to a frame, Two moveable treftles We filter mounted upon “fionally for :s removed 0CC a - This apparatus be mo bi a & convenient place. See = to the mo Sa : le in a laboratory, TE i i tant article 1 £10 5 i : s the Chg ry i Hired within peach : rd oe | Cw lace near ! ne place 1 ies about 1t W Je lice which 8 the laboratory, : | place vy thing boratory together With oe ie ais ¥ OE t for kindling fires quickly. 1 enient res : ame time, for containing be po 10 wanted fuch as furnaces eriments : P The mot convenicn - LABORATORY clay, quicklime, fand, and many other things neceffary for chemical operations. Laflly, a middle-fized table, with folid feet, ought to be enumerated amongft the large moveables of a laboratory, the ufe of which is to fupport a porphyry, or levigating ftone, or rather a very hard and denfe grit-ftone, together with a grinder made of the fame kind of fone. The other fmall moveables or utenfils of a laboratory are, fmall hand-mortars of marble, iron, and glafs, and their peftles ; earthen, ftone, metal, and glafs veflels ; an enume- vation of which fee under the article VEssELs, and a defecription under their refpective names. Some white writing-paper, and fome paper not glued for filtrations ; a large number of clean ftraws, eight or ten in- ches long, for ftirring mixturesin glafles, and for fupporting paper filters placed in glafs funnels. Glafs tubes for ftirring and mixing corrofive liquors ; fpa- tulas of wood, ivory, metal; and of glafs. Thin pafteboards, and horns, very convenient for col- lecting matters bruifed with water upon the levigating ftone, or in mortars ; corks of all fizes ; bladders and linen ftrips for luting veflels. See Lutes. A good portable pair of bellows; a good fleel for ftriking fire ; a glue pot, with its little bruh ; laftly, a preat many boxes of various fizes, for containing moft of the above- mentioned things, and which are to be placed upon the fhelves. Befides thefe things, fome fubflances are fo neceflary in moft chemical operations, that they may be confidercd as inftruments necefiary for the practice of this fcience. Thefe fubflancesare: All metals and femi-metals, which ought to be very pure: ¥itriolic acid, fome of which ought to be concentrated and rectified; and alfo fome of that fort commonly fold by druggifts. Aqua fortis, fuch as is commonly fold, and is cheap; alfo fpirit of nitre moderately ftrong, but very pure: the fame acid very pure, concentrated, and fmoking. Common fpirit of falt. Some of the fame acid very pure, very flrong, and fmoking. All thefe acids ought to be kept in cryftal glafs bottles, and clofed with glafs ftoppers. Some diftilled vinegar, which may be kept in zn ordinary bottle ; fome radical vinegar, which ought to be kept in a bottle with a glafs flopper; fome cream of tartar, in an earthen or glafs veficl, or in a box. Common LABORATO RY _ kali, very ary ’ Ee EE oi ‘bottle. The fame al eg uid fate. -_ e {alt of tartar, or : 4 that 1s, W€ Commo | and fome liquid. {olution of foda. The va 1! formed cryfals Nineral alkali, liquid; the dry and very pure; teal AE by . ’ . € . of foda. kalis liquid, and TeRCE Tl re cauftic, The two me particularly iets which Some phlo- quickhime Kept in bottles with glals to as to be fit for ought Wn or cven faturated, ~ifFicate ’ : gift p Profan bIUE: yt in a well clofed bottle Some i! Jigs Some common Gi aged by a fixed The fame B48 kali of fal ammoniac, CUERSTE L hith a Very PUT S13. and fome liquid, kept alieali, fom ; d by quicklime, as lafs ftopper- iac difengagee. pt of nor {pirit oF of this Tpirit may be kept © trong as 1S POMBE \ . d bottles. (s {trength. «A in well clofed le Lime water, and a eid fpirit of wine. Ged vigiaic anes Retified oferta oH ns in-water, Calls 3 paper ; river or So a folvents, cer- Befides thefe fubftances, oR & which are frequently hed a on or ar dficully preps RI alum, and ‘ it itre ; decrep! ) diffolyed 10 iti ‘1 of olives; foap. rpentine ; oil 0 foun yy Sndure of turnfol, or turni > 0 iv calcined alum 3 geen i ated common falt ; fo . diftilled water ; pu! e: a Vitriolated tartars blue vitriol 3 n of he ee ALE d borax ; fedative falt, triol 3 \ py 3 EL lution of fied fal ammoniac; ¢ filver in fpint of nitre; 2 fot fe {olution o : antimony. i A PTE © he fame acid 5 butter of ZHUTNLIL coe bli mercury bottles with glafs foppers: be kept 1 . ? {and wafhed nate. g ply . " : Cerufs ; litharge ; minium olafs of lead; g hit marble; washed chalk 3 & thefe matters un de salir e and properties ge {t ¢ | rit ‘ve name ned initr pellive names. g “+h the above-mentio ded with t oh any J . A Vv I Vor. IL ‘calcine and ground ; lafs of borax. der their re= ments rv > C= chemical exp al {alts which oe — i ———— : Se ———— LABORATORY which have not been named ; but all thefe falts with bafes of earths, metals, fixed or volatile alkalis, may be eafily and in- ftantly prepared, as moft of them do not require diftillation or fublimation. They may neverthelefs, if they arenot too numerous, be all previoufly prepared and kept ready for any occafions. i | e ought not to finifh this article without making fome obfervations important to thofe who propofe to give them- felves up to the ftudy of chemiftry. They ought to be well perfuaded that method, order, and cleanlinefs, are effentiall neceflary in a chemical laboratory. Every veflel and utenfil ought to be well cleanfed as often as it is tifed, and putagain into its place : infcriptions ought to be faftened upon all the fubftances. Thefe cares, which feem to be trifling, are however very fatiguing and tedious ; but they alfo are very important, though frequently little obferved.. When a perfon is keenly engaged, experiments fucceed each other quickly ; fome feem nearly to decide the matter, and others fuggeft new ideas » he cannot but proceed to them immediately, and he is led from one to another : he thinks he fhall eafily know again the produéts of the firft experiments, and therefore he does not take time to put them in order : he profecutes with eagernefs the experiments which he has laft thought of ;.and, in the mean time, the veflels employed, the glafes and bottles filled, fo accumulate, that he cannot any longer diftinguith them; or, at leaft, he is uncertain concerning many of his former produéts. This evil is encreafed if a new feries of Spererions fucceed, and occupy all the laboratory ; or if heis obliged to quit it for fome time : every thing then goes into confufion. Thence it frequently happens that he lofes the fruits of much labor, and that he muft throw away almoft all the products of his experiments. ‘The only method of avoiding thefe inconveniences is ta employ the cares and attentions above-mentioned. It is in- deed difagreeable to ftop continually in the middle of the moft interefting refearches, and to employ a very precious and confiderable time in cleaning veflels, arranging them, faftening infcriptions on them, &c. Thefe employments are capable of cooling or retarding the progrefs of genius, and are tedious and difguftful ; but they are neverthelefs neceflary, Thofe perfons whofe fortune enables them to . have an affiftant operator, on whofe exaétnefs and intelligence they can depend, avoid many of thefe difagreeable circum- {tances ; but they ought neverthelefs to attend to the execu- tion of thefe things. We cannot depend too much on our- felves in thefe matters, however minute, on account of their confequences, LABORATORY . difpenfable when the : is becomes even indifpeniable WRC - conferees {di kept fecret, at leaft for a ime; which exper :n chemiftry. wk is often ne os inquiries are made, She mx ys and produdts of all the I ior Tre on time, iftin&tly a By oat phe- £ MEP time, frequ ; thefe things, when kept To enal: Many hne difcoveries na that were not at ail Hu/prer acovaries Te have been made in this manner, and many in ck ; } Pein certainly been loft by throwing away too haftily or neglecting the products. d to chemical ope- t too much recommen hem! | af: Tn upon their guard 2geint mpofing i ail experiments, which frequently prelen an : : " felves in practice. A circumitance feemingly SL elv or not eafily percep tible, is frequently Sufficient 45 4 ug the ance of a greatdifcovery, by Sheans Of Signe appearan rthelefs, are found to proces rom oie wa ‘Chemical experiments depen on ee all of them can feldom bea ged 0 nd He ne or de ao experi- We therefore muft not decide e experiment muft be repeated doubt can remain. for the improve i . as it prefents profpeéts of ma- pe, J Don io apply their ny ufeful and pai. Siro exceedingly circumfpect not to xpence of money and time. Thofe 1 with the philofopher’s ro th Xo they fuggeft, are alfo In a certain fet of experiments impofing appearance, although fomeoneis gunstelly <5 permite is full of thef hal fo Fy hich ferve only to deceive the unwary, to mls ner of trials, and to lead to great x pees oo ore he fruitleflnefs of the fearch be difcovered. J yiheie io ie we do not intend to divert from all us Isles 8 hofe whofe tafte and talents render them fit or he yj ga Ie ontrar we acknowledge that the improv 5) rane : os and be difcovery of new objects of mam AEE os po are undouiesdly the fineft 304 pee ang 1 and whic ; Pole A thefe iii what would chemiftry be but a that very different refults pro ments, and at different es after the firft fuccefs ; but = pert {everal times, and even varied, ti S00 Further, as chemiftry offers many tone, from the hc tended with fimilar danger. {cience 2 —— = A ——— EN —— \ LAC {cience purely theoreti he eo! tical, capable of em i abfiraft sod Far unaiye minds, but pig oy, fe ge alfo, that the fuccefles in this kind A 1 ica inquiry are not ; i y a rare ; and that their authors have fometimes acquired fortunes, fo m fhe fr wits of hele oe oh a 3 bog RbDtas the < i ihe more dazzling and near a; 4, ft CeHBty. cumfpection and even diftruft is Se “LAC LUNE. (n) edn LAC. (2) (2) Lac Lenz, 4, ; . friable, and =, Agaricus Minerals, is a very li RE us). White calcareous earth. See re ss % 0) Lac, Lacca, or Gum-lac, i . ? {peci ’ um-lae, is a kind : . £ Eley OF Minged ants form cells upon a f which 3 or ca hike ena {ome of the dead infelts which em A eAdLot} 0 e bilsnes of the lac. That called : . red which 15 un i we: ome of the {mall branches of ea g. ehagiss hering Ricks aid ie if {Tas lac, when feparated Oe oad digeftion th on go sly powdered, and deprived ake ita Pe ad- poles, is called ad for the fake of dyes, and a ory fom Inde fe -lac ; and laftly, when the LL fpr; ek i) 9 Feling it over a gentle fire at reed Yifficaltly ny alle Sell- ac. Lac is unfoluble # wat ormed be well de hie em {pirit of WINE, which for that pur i asd of dian oa. According to Neuman Fl § malt ar Af Sin ed in an open fire, yielded nine arte ind fix RR ee thick oil, one ounce fix drams of and #3 EE a oe Sk alkaline, and a refiduum weig hi Watery for the makin of ; logiey in the preparation of ie Sarmiihes, dying fearlet Th : Selina and as a coloring ai le. or k e color given by lac is lefs beauiful, b Be matter of the 1 at Brel by cochineal. To render ihe ® Tp ! ftuffs to be Eh aa in water, fo as to be a fied Drang fone. powder > Py Hellot directs the following DT ie jhe LL ered Sum ac be digetted during two hours - ! dee tothe wate? Airy Jeet, by which a fine crimfon or io A this a! ’ he gum is rendered pale or res given ard when Done | off clear, let a folution of alum be add = gid when tis coloring Srengs LL ee Taree quantity of lac goon In dried. , It il weigh about A 3: . : is drt ; . diffufed in warm water, and fome Jed feat yt Be -adde , q q V - u 8 to be added to a foluti Lo posts dye is prepared. ution of tartar in boiling water; and thus the LACQUER. LAPIS ACQUER. (p) LA UE FRNALIS. See CAvusTIC L LAZULIL APIS (4) % LEAD. nifhes applied upon tin, brafs and other om tarnifhing, and to improve their olor’ T << a {olution of the refinous {ub- ftance called feed lac, in {pirit of wine. The {pirit ou very much dephlegm order to diffolve much of the lac. For this purpofc, forpe authors dire dry potafh to be thrown into the fpirit. This alkali atrraéts the water, with which it forms 2 liquid that fubfides diftin&ly f the {pirit, at the bottom ©! the veffel. From this liquid irit 1 d by de- cantation. BY this method the {pirit 18 much dephlegmated ¢ but at the fame time, it becomes impregnated with part of the alkali, which depraves its color, and communicates 2 property to the lacquer of imbibing moifture from the air. Thefe inconve- niences may be P by he fpirit 5 OF, if the artilt | 1 hat procefs, he may cleanfe the {piri adding to it fome calcined alum, t 1 i ing with the alkali remain- a vitriolated tartar, which, not ing in the fpirit, folable in fpirit of wine, falls to the bottom together wit the earth of the decompofed alum. To a pint of the dephleg- mated and purified fpirit about three ounces of powdered fhell-lac are tobe added 5 and the mixture to be digefted during fome days with a moderate heat. The liquor ought then to be poured off, ftrained, and cleared by {erding. This clear liquor 1s ROW fit to receive 1 oring {ubftances, the the required color from certain refinous col inc mboge, annotto, the former of whic er an orange color. In order to give of gamboge aré added to one of an- feparately diffolved two parts loring fubftances may be in the tin&ure of 1ac, and the color required may be adjufted by mixing the two {slations in different proportions. When filver~ leaf, or tin, ar a larger quantity of the coloring materials are requifite than when the lacquer is intended to be jaid on b fs. Lapis LazvulLl is a blue ftone, generally white veins and gold-colored {pots. Wallerius confiders this ftone as a fpecies of jaipers and Cronftedt, more juftly, asa fpecies 9 that order of earths which have been lately called zeolites. See ZropLiTES. Mr. Margraaf, and alfo Mr. Cronftedt, have made iments on this ftone, carefully cleanfed from all white, PY" . or heterogeneous matters From thefe experiments WE 1. That this ftone is foluble in acids without effervefcence 3 1 calcined, it forms gelatinous mafles motto; but t intermixed with learn, and when it has been previoufly H 3 rs so ——— LEAD LEAD. Lead, called alfo Saturn, is an imperfect metal, * white, but darker than tin, the fofteft, leaft ductile, leaft elaftic, and leaft fonorous of all the metals. It alfo has the leaft tenacity ; a leaden wire of ox of an inch a diameter being capable of fupporting only 293 __ pounds. This metal has a confiderable fpecific gravity. Next to gold, platina, and mercury, it is the heavieft metal. Ft mafles with acids. 2. That by calcination it is not deprived of its blue color, till at leaft that operation has been long continued. 3. By a violent fire it is fufible, and forms a frothy glafs, fome- times whitifh, and fometimes of a dutky yellow-color, but always clouded with blue fpots. 4. Fufed with nitre, and thrown red- hot into water, it tinged the water with a blue color, which dif- _appeared in fcme hours. By this operation the ftone loft its blue color. 5. Some of this ftone, powdered and mixed with glafs frit, produced a tranfparent citron-colored glafs. With borax, it produced a glafs of a chryfolite-color. 6. It gave no figns of its containing copper, notwithflanding it has been confidered as an ore of copper by moft authors. 7. It thewed marks of iron, by forming a blue precipitate, like Prufian blue, when a phlo- gifticated alkali was added to a folution of this ftene in acids. 8. Margraaf fays, that by adding vitriolic acid to folutions of this ftone in nitrous and marine acids, a white precipitate was form- ed, which he fuppofes was calcareous earth. Neverthelefs, Mr, Cronftedt affirms, that this fone does not effervefce with acids. Perhaps the calcareous earth was not effential, but only accidental. 9. Cronftedt fays, that a precipitate is formed by adding a fixed alkali to a folution of this ftone in vitriolic acid, which, being fcorified with borax, yields a regulus of filver. He fays, that by {eorification with lead, two ounces of filver have been obtained from 2 hundred pounds of the fone. Mr. Margraaf does not mention _ that he found any filver, or that he fearched for any. Perhaps it is only accidental. The fine blue fubftance called w/tramarine is prepared from lapis lazuli in the following manner, according to Wallerius. The flone, firft finely levigated and mixed with linfeed oil, is to be added to a pafte, made by mixing together equal parts of yellow wax, - colophony, pitch, thatis, half a pound of each, with half an ounce of linfeed oil, two ounces of turpentine, and two ounces of maftic. To three or four parts of this pafte one part of the levigated flone, mixed with linfeed cil, is to be added ; and after the mixture has been digefted together during three or four weeks, it is to be thrown into bot water, and ftirred till the blue color feparates and diffufes in the watér, which is then to be poured off, The blue matter is allowed to fettle; and, when dry, is the ultramarine required. lofes, Yofes, when LEAD ii: metfed in water, peewies hina » e A gs 0,8 i its peculiar (mell and tafte. » . e a - metals, it inftrument, 1tS furface 2p put it quickly tare s covered by a flight Tr than iron lon forcit is ble, and melts that is, before : ry fufi opper a or copp at as tin; decompofet t ‘ nearly wit heat that is requifite, it is red. {h afhes are formed, 11 it calcines; ability of lead the fame ma fufibility and cali Cl wainte The color ’ qualities in tifa PC of metals being Rshat and fuperf : with only t analogy iublt Stids © AY ed “hall {hew that the proper thofe r 2 . : t. s 0 ols are effentially ge lead, fimilar Ei The grey calx, or £5 nt appearance, ! x them be of tin, be erate that jue epofed to flame. nation with 2 he . ey ee they acquire at continued, and P re white, Tnftead of becoming then called mafficot, lor, and are intenfe, and : By : i comes more and ONS red lead; which ead. : is then called miniutty tle fire, 1t Jaft ony of ng this calx with 2 cd fubftance, ee. m i llow vitri ; be fufed, it then eafily melts jaa ys of talk. Lead in this compofed f thefe two of fmall’ fcales like thls This happens In bi fate is called litharge J ¢ : pi Be . 1 . . . . opetalies SS ary (0 ative and fluid, to a true glafs, compact crucibles. changes fi s like water throu of lead, becaufe x Talcined and melted 1S © ctlenefs, and all the effen- Lens ie the tranfparency, bri ufeful in many arts, as in 1a y sv f LEAD. er tial properties of glals. Os fufible der the artici€ £'1ead is the moft fulibie, € pl Ee Neale calxes, that 0 2 hich Nek i f tin, which is very re nd moft eafily converdble je go . e differs effentially from t x fractory. H 4 LEAD This difference proceeds from the total privation which tin fuflains of all its phlagifton, and from its capacity of a radical or perfect calcination. Whereas lead, although it Jofes, as, eafily as tin does, as much of its phlogifton as is Jegeflary to deftroy. its metallic appearance, and to calcine or vitrify it ; yet it retains enough of its phlogifton to pre- ferve a great fufibility, and even a confiderable denfity : for all the calxes and glafles of lead are very heayy. ’ All thefe calxes and glaffes of Jead are eafily revivable. They can Acarcely be melted but fome part of the lead is revived, although no inflammable matter has been added, This alfo is a proof that they retain much phlogifton. For, in general, all metallic calxes are fo much more eafily re- ducible as they retain more of their inflammable principle. .. Lead is foluble by all acids, and prefents with them phe- nomena fimilar to thofe of filver with the fame acids. Lead combined to faturation with nitrous acid forms, as filver does, a cryftallizable. nitrops falt with metallic bafe, called zitre of lead, "This falt is, capable of decrepitating, and even of etonating without addition of inflammable matter, as feve. ral chemifts pretend.. This detonation muft therefore pro- cecd from the phlogifton retained by. the lead, which: is fufficiently .combuftible for that purpofe. Kunkel, who feems not to_have known this property of nitreof lead, relates, in his Treatife on; the Art of making Glafs, that when he attempted .to diftil this (alt, his retort was fuddenly burft with great noife and danger, Several chemifts, among others Becker in his Second Sup- plement to. the Phyfica Subterranea, and Kunkel in his La- boratorium Chemicum, give procefles by which mercury may be obtained :from lead. Mr. Groffe, who mentions chefs procefles in the Memoirs of the Academy, gives one himfelf, which is more fimple and more eafily tried, fince it confifts only in faturating perfectly fome good nitrous acid with lead. By meansof this faturation a grey powder is precipi~ tated, according to this chemift, in which mercury is found. But this procefs probably does not fucceed with every kind of lead; for Meflys. Macquer and Beaumé fay, in their Courfe of Chemiftry, that they have repeated, with all poffible attention, this experiment of Mr. Groffe without having ob- tained mercury, | : Pure vitriolic acid, and that contained in neutral vitriolic falts, ‘when mixed with a folution of lead in nitrous acid, unites with the lead, feparates it from the nitrous acid, and forms with it-a metallic falt, or vitiol of lead, which cry- 3 ftallizes, 7 . d app ftallizes, 20° °F ‘when the liquor 5 He falt is the {ame as that : tity of water do not contain a fuficient QUARRY Fr) folve it. TRS EA TE 7 Hk it, pier to dill ly lead invite A ral flts confaining its PIE: "Karin acid, © 4 its folution in pitrous acl Ae ead fromifs fo § RO m aorneumn, from .cipitate alfo lead, tallic falt called p bub combination © . 11 2 metas x wit Oe ith it, forming that it has Plumbum cot the many refemblanees B68 0 cornet: 1 more foluble in He vr much me hee a int acid, or that % 4 than in the luna co {everal other ing the volatile alkali it has . hér metals, it 3. for, like A method, Mr fal a ofing this falt. X ch he employs the property x s the Dlumbum corneum W rgraaf make ho{phorus. . d in nitrous ration of phofpherte; the {olution of lez that a mas "Several chemifls a8 fed by water fing manner as acid may, be dec be thus formed, 10 ¥ So examined the giftexy of lead A Mr. Beaume, W ig precipitation chat of Rifas + 0 racy, found, that SE DRED ris affair re when very P is to be atiri- des pore ge confequentiy icularly to t fed pi falts, and past ters. ly the buted 1 moft all ordinary Wig .d with eafe; but op ¢ tained in almoit ds alfo diflolve lea are known, becau Vegetable aGiCh C0 cial with vinegar The firft of thefe combinations 0 fr dicine and in the arts. It is akind of thefe are ufed in MECIE™ ufss OF white- lead. de by the acl : hat Fp white Colt a oid. The m . e S "Ns the vapor of which h¢ 0 CE and isthe of vinegar, 0.1 cparation is for pain arpofe, although it chief ufe of this p Pi (covered for that p hat it gives painfu only white hitherto The firft 1s, t 5 t has two very gr€a nd ployed i pen colics to Per 07 Ro become yellow of Piet is, that 1 s ] b aut in tim ’ , z i i ] i . The difcovery t wi confequently I cole, TS and other advantages oO : eile Soneies would walk hott its ngorvemenicies, Lo, See CERUSS: lead, Wi and even to {ervice to painting, ure, that is, Sit + nrecipitatio A ol this precipit he felenites cont ruft of lead, of an 2 be of important Cerufs LEAD Cerufs contains too | ittle of the acid of vinegar t6 be ix the ftate of a neutral falt ; but as it is lead much opened and divided, it may be eafily completely combined to faturation efted with this acid.” For this purpofe cerufs muft be dj vi fufficient quantity of The liquor after be filtrated, eva cryftals are formed, capable of a faline, metallic, and fa falt is called Sugar or falt of lead. Salt of compofed merely by’the adion of fire. very concentrated acid of vine a kind of radical vinegar, diftilled vinegar, to diffolve this folution is called Vine of a perfe& folution in fimilar to th at obtained from cryftals of copper. See SALT of Leap, Oils and fat matters, which in ing upon metallic fubftances, h upon lead, and particularly upon its calxes. In confequence of this ation, cerufs, minium, and lithar €, may be entirely and copioufly diffolved in moft oils by coction with moderate heat. Oils ‘in which Jead has been diffolved are thereby rendered thick and drying. Linfeed oil thus thickened by ead is much ufed in painting. The painters call jt drying of lead may be diffolved in 5 is thence formed, which when cold is folid, tenacious, and of the confiftence of plafters. The con- itence of many of the plafters ufed in furgery is caufed by calxes of lead diflolved in ols. Thefe maffes of lead comn bined with oil, or plafters, refemble foap in fmell, rancid tafte, milkinefs given to water, and laftly, in bei compofed by acids which unite with the lead, and the oil from ijt. Thefe obfervations were made by Mr. Geoffroy, ly united to fulphur, and is eaf; xpofing it at once to the a&ion of ly burnt and fulphur, fire, fembling the fulphur, This metal eafily unites with all metals excepting iron, with which it cannot by any means be allayed. Such is the antipathy of thefe two metals, that if filver allayed with fome iron be melted with lead, the lead prefently feizcs the filver, and the iron floats upon the furface of ote melted metals, everthelefs the calxes of lead and iron are very well united together by fufion, and the former facilitates the vitrification of the latter as much as jt does that of the calxes of other metals, | ‘th tin is moft u he hat with tin 1S me I lings of lead, t Of all the employ allay of le ftrong © mele ely than either calx refulting fro and glazings fore 1 gar o porated, and cryftallized, fine water, ccharine tafe, from which this lead may be de. By diftillation a are filver an gar may be obtained from it, they i being incapab ; , d into general are capable of act- ufed and formes) 0 hee ave a diftinguifhed a&ion sonduding ye medicine, hen taken internally. LEA V ES i oy H m be employed to porfy Be P ne Joe ed os | as from other 1mp ft bei inni n by plumbers, and for tinmng. If a yp . ly fire, fufficient d to an opel thefe two ad and ” Bie and to a quickly the Ie Li ther m i on and cen OSE TG Fly. The . ion isthe balis © m this operation hen ware. Itis called pe froy’s Table, for eart d, according os Gellert’s Table, The affinities of jegd> according T yo marked in this d copper: onper. I 2 filver, gold, Wil» f umtingwith lea: ¢t ufe. Itis : leo rations arc PR ning an : or : fheets and PR gardens. Lead 1s Ho . ily, from the co . ed for foldering Lead and its feveral prepa . ons w : it occaft fies which 1t ¢ ns are very m its fedative, Cp and the fugss d plafters which iin wy 3 offefs thefe qualt ie . : o ed in painting Wi in the t is alfo ufed In t bor oo : nin flux, and wakes prpaion of dls ag oF PT ttery wares, from t reparation of ena ia nick a ” : ie heb geste tind to the fineft. Laitlys BJ moft ordi fla ned and € Js are ref lly ufed, fect meta is fo generally at the the moft per that this metal is f 5 ve mentioned, th ! therefore fay, important arts Wwe » ceffary in ei not exift without 1t. blo HER (FOSSIL). (7) LEY LEAVES. (s) ia liated This is a fo vl , Allutn IIERG, CL athens BF A ry Lestuse (Foss “hoe fibres ne it. For the Pro n amianthus, cont fparry cryftals € t contains P quently 1 AMIANTHUS. toe a” Gols rties of this ftone, fee pe : 7 en Leaves. The follows dig ML EAVES. &i 5 Jeaves are taken = Ged by re ing btinces of of plants Bay es are genere colored, or color 0 1s. The fpiritu mfelves are ine long in wine oki a when , e J {eldom remains thefe deep green, The co! : ith, or hoary. yellow: ’ and pal 1 its externa “LEY (CA iB CAUS HOHL.ERS nie) or the LEY 6 5 1 rendered cauftic b e 18 given to li » of SOAP. A y quicklimie. To ys of fixed * a c o mixed with one part of quick. quicklime a . N re adde J I2 or I§ times Wo IS to be put IS quicklime i and the le " boi me is to be thu paper fit peer hot is to Oke daring fome i Sakats; centrated by Vapor upon linen, hn through a a] Judged neceflar ation upon the fir e ley is to be ¢ n figned, Ys according to the ie ye fuch a degree ne Quicklime h ble op which Jv iy 11 as th it 1s de- caufticity of all fixed alkalis : and Tore] | only by taking fr alkalis : and this is ro confiderably: th matter, but a part al Hen Tals this prolniily ra art alfo of that which a inflammable nto their cons thefe li freemen gives ated in a folid om time when the col here, Alkalis a green ts eipaled to air, The 4 Tend and acids weak n. the. colors of the put than: any ott ; 0 or. Limewater im en, deftroy, or chan. ‘tinctures and of th He lan, ha means of Tim the color, and gothom i 12 brawnifh feveral Sr the leaves of nelegant or ability of ved her plants of acanthus, I; green lakes m gréen color t . Few herbs comin illy of the all, ay be deep. Ne 0 water; perhaps communicate any pact and of ‘ ps none gi any part of thei the leaves ye a green dye i give a gr of their fome ve is fa green confider: Sto non OE hy of the Hk Je Sven to wolleey er 8 and trees oi y evil's. bit nervil, or cow- a iw i aie BL tuned particularly affords x in ich have : erves, th affords peach, and an aftringent t fle at all leaves, b a fine arable a id trees, ath-b afte, as the le » barks, and - low ark, roo - leaves of th fibflance s- From the | ts of wild pati ¢ almond, . are 1¢ leaves of Datience, &c. vi 7 fo. Dell, fates eed pamelys oy Soplase, blue ne many other veg a fimilar blue fe woad ; which Yegetables to a He as maght be ok i ther the Py a mixture of blue re color of » 0. r, \ «iQ < y “ juice of the Pa be capable of refifti yellow parii- . 5S, W 1 n > a Sngation. Dr, foe the yellow ge } ye€s from other plants E> tried, without {i efiroyed by that fe » Dy putrefying them rcs > to obtain oe : 4 ater, pofition LIQUOR ofition a8 2 pri Hence 2 confiderable alteration is toduced upon quicklime, fimilar to that roduced upon vO + ‘and we may confequently de- compofe entirely j q But thefe ex- i | ./s The: pro= been fuffici- , upon oily. mat- re therefore thus pre= d with oils for the for= furnifhes an alka- 1ted in a crucible fe when it is ap= and leaves 18 diffolving power © ters, 18 much encreafed ; and they 2 pared; when they are to be combine mation of foaps: (t The cauftic ley, evaporated to drynefs, line falt excee ingly acrid, which being me becomes what is called common car ic 3 becau it makes an efchar, pierces it, hich, when continued, lied to the fKin, ration of wW folving pow- an ulcer, the fuppu called an iffue. Cauftic alkali has not only much greater di er, but :¢ is alfo much more deliquefcent, and attracts muc more powerfully the moifture of the air, than ordinary alkali. I hefe properties muft p the developement of the {aline principle by , See ALKALI L1LLY oP ACELSUS. se TINCTURE of MET ALS. se QUICKLIME. ER (LIME). LIME. LIME- LINNE LIQUOR Sl feparation of this liquor € dercd flints or fand with a fufficient fo that a compound refults from it in the alkali prevail, and particularly a tot For this purpofe one part of ground fl well mixed with three or four parts O fixed alkali. The mixture 1s tO be put into a crucible which ought tO be very large, in proportion tO the quantity of matter. Fhe cruci= ble is then to be placed in a forge or good melting furnaces and gradually heated. (t) The effec produced upon alkalis by quicklime is the ab- forption of their fixable air, Or gas. See Gas and ALKALI. (#) LINNEN (FosstL), is a kind of amianthus which confifts of flexible, parallel, foft fibres, and which has been celebrated for the ufe it has been applied tO of being woven, and forming an, incombufhble cloth. Paper has alfo been made of it, and wicks for lamps. 9 AMIANTHUS. When w ATER. Se WAT N (FOSSIL) u) ICUM. LiQUOR of FLINTS. The onfifts in uniting by fufion povi- quantity of fixed alkali, which the properties of al folubility in watet. ‘nts or fand is to be LIQUOR When this mixture has ac fiderable boilin are obfervable, the action of thefe two matters upon each other, vent the matter in this ftate from flowing over the this ought to be large, and the fire gradual] : part only of the mixture may be put into the once; and when its effervefcence is over, added at differ the reft may be taking care that ea ch portion to be melted matter. When the effervefcence of al} the mixture is over, itis to kept in a good fufion during a then to be poured u quarter of an hour, and js pon a greafed ftone or plate of iron, The matter when cold is brittle, and feems vitrified. It is even tranfparent like glafs li is onl It quickly and ftrongly attra@s moifture from the air, and is entirely fo- luble in water, except a very {mall portion of earthy matter, But a fimilar earth is alfo always feparated from pure fixed alkali during its folution in water, ~The filtrated folution is at firft clear, and limpid ; but it afterwards becomes turbid, and forms an earthy fediment, like that formed by folutions of fixed alkali, feems more co only the former pious. This liquor has al] the properties of liquid fixed alkali. All thefe properties of alkaline falts, and particularly its total folubility in water, are caufed by the quantity of fixed alkali which enters into this kind of vitrified matter, compound bodies partake always of the properties of their component principles, and as the properties of the principle which predominates in the compofition of any body do alfo predominate in that bod » We may perceivewhy the properties of the fixed alkali in the prefent combination thould be more fenfible than thofe of the earthy matter or flints, The alkali communicates to the earthy matter fome of its ftrong difpo- fition to unite with water, The flints are really kept dif- folved in water, and by this experiment they are confequently i ence it has been called the liquor ded to the liquor of flints fo as to faturate the alkali, the flint which was kept diffolved in water by means of this alkali will be now precipitated in ftate of a fine earth, Mr. ' Pott mentions a very fingular phenomenon which happens in this experiment,” which is, that this earthy precipitate i s entirely foluble by acids ; fo : that when the quantity of alka double or nearly double the quantity of flints. quired a certain heat, a cone g and {welling occafioned by To pre- crucible at LIQUOR : cent to faturate the id be ‘added than 1s i ih (x) : that if oo recipitate will entirely diiap alkali, the P d even when : 3 aturalftate, an ds, are fable earths in fhe? oe mechanical feo lids, uch as is pot they become foluble ficient and 85 hey by fufion drat a ; co \ n Oo, have kaliy they mit “Tis property with uantity © jon in this operatiof: roceeds either from ular alteration ing in acids, P ced, or from a be acquire of Gin “their parts wg: of its principles eat fipels 9 fixed alkali, or WEY which they cannot {mall portion © with them, and fr pele; Plo cnt 0 i by fe pas combination re be entur 1kali which e The fixed 2 . one part itrifiable earth ; 1fo fome alteration from the vitri ceives allo 1 P 2 . e. : hat is ob- : ¢ was befor fimilar to W uftic than 1 ing happens It of flints. more cau : fomething the liquor Juak fons ake In vitrifica h alkaline falt Po Shei r fuftained 2 alkali, npofition, OF intimately with ¥ an alkaline pin fire to uni irra ATION. are partly fob} d moiften in the air. x G) of LIBA- ts tarts Ror SPIRIT (5 MI acid very Eoacen LIQUL A reparation 1s a m ith much tin. 1t1 vi Tre and mpseguaied Wl corrofive fublimate trated, II “ation from a mi diftillation Vow btained by i tus. an amalga with Hin, fmoking liquor of 4 wi of mercury : To jake he four parts of tin and f yor equal weight of muft be made of one well mixed yb al together in 2 this amalgam 15 te, by triturating the t into a glafs retort corrofive bitoni mixture is to be pu nace. ‘To the retort glafs mortar. d in a reverberatory far a {mall hole in 1%, which is to be Dn fat lute a receiver ya @tillation of concen-= is to be luted wit as is done for the Ht then to be begun in the fame MARNEE "= Topp diftillation is A very fmoking trated mine) gee well managed fire. with a gradu As vitrl » that : umé fays | . but Mr. Beaun Faitate : . ous earth; but ¢ this precip Flay ands 3 2 aM. Monnet pa ge faic 1a bafe du Jed eastn i Ri -Memoire {ur la err - in . is not foluble | Epfom, par M. Monnet. Rozier, june 1774+ Sel Eplom, pa ( liquor : ven concrete matter. When the operation i : s finifhed : poured quickly i ed, the lig PR ¥ nto a ¢ryft: quor in the recei . yital glafs bottl eceiver is to'b x e€ with a glafs a oe per When thi 1 this b : ottle is opened, 2 Whi ; fhe white, copious, thick. ? A / v 1; . - without difappeari ppearipg. . he y 2 I rofive fubli . imate ui with the tin; ase mercury in this experi with it. in diftllation maf seals OT ToL une pb uantity of the tin paff; oft metallic ol perty of taifing efs this acid is Torr es over in this Gini, a confiderable HE and bk etn faturated ib Neverthé- od way. From this oh di olving much as 1t 1s {till ne great concentrition perfect faturation in the ordi- oking fo confiderably Proceeds part] it together with froresly concurs to ss eer tielels or 0 of : or mokes . = 4 118 pro . other i= in erty, caufe fpirit of falt, ly more re Ts For although this » twithftanding mu hl Glauber’s mentor oft concentrated difference betwixt ot hs elaftic. AGE Its vapours are for as by mixing he orp nd concentrated oi effentia} irit of wine ormer, b pirit of (Mauing) » Marine ether may be Phi Ren with aftly, if ¢d, Sec E ; s I we attem . THER 23 mu tii pt to d ge ich tin in concentrated Sn by the ordin oking liquor of Libs d fpirit of fajt as i ary method Sige rendered m 1 Pv, this acid > Smieingg in the A real differe ore Smoking us Jo far from le] 3 nce 59 ceales 1 cin impregnated Aes Sherine fubfifts Be anny to fimoke, fublimate, and by LL an decom e marine acid with tin in any othe itillation, and the m: ion of corrofive mine whence this anne, Bit wot arine acid treated jue in the mercury ke erence proceeds Dado eafily deter- that be th r in the ti es this acid date. wi in fome of ; Is acl depo- this experiment I. is what principle is a principles ? If earth? Thefe queftion with phlogifton ? or impregnated in refearches s cannot te decided without furip. I'he fmoking li Without fi oking li ; urther concentrated 3 hauopies all the other properties o sia, If it bediluted EG when TNE a of the moft feparated from it in oi much water, moft y: aturated with 1s. mixed with a foluti. e form of white li he i tnwill bit purple precipitate bas gold WERE GU when it affius, as all other hy forms the lutions of tin: > and ahd even PURPLE) earths; an in thofe Ww folved by marine acid. The nece of Libavius is not very tr ration 1s muc nthe diftillation fpirit of fa clafticity and exp For the diftillation © tin is previou mated with mercury, ftate it 1s if the di after the butter of tin, tion of tin with mar from the corrofive fublimate ‘may be (MARINE); TiN, HOFFMAN. cine only, is ether, and of a little of the of the liquor and afterwar of the oil which ri what is called LITHA RGE See PRECIPITATE pure tin not diffolved, -do- of CASSIUS. It may be precipitated by abforbent, In feveral dyes, particularly ¢ produces the {ame effcts as tin dif- See DYEING. : a fTary management Fok. aki king fpirit oublefome or diff This ope- y fmoking, f vitriolic acid, from the greater ce of the vapors of the latter. {pirit of Libavius, the becaufe in this fily mifcible with corrofive fublimates d the heat increafeds ftillation. be continueds an or the concrete part of the combina- has rifen, the mercury revive obtained. See ACID and CORROSIVE SuBLI- R (MINERAL ANODYNE) of [his compofition, which is ufed in medi- rectified fpirit of wine, of ¢ vitriol. This he {pirit of wine nd by alka hich arered, 1 h eafier tha it by means O anfive for f the fmoking ly amalga much more €a ine acid, MERCURY, LIQUO a mixture of very {weet oil © made by mixing an ounce of t (es firft in the diftillation of ether, with as much which rifes next, and which contains the ethers ds by diffolving in this mixture, twelve drops (es after the ether has pafled. This 1s the mineral anodyne liquor of Hoffman. It he fame virtues as the ether, which phyficians {ubftitute for it. As ether and oil of {pirit of Je from the nitrous, marine, and acetous acids, liquors may be made from thefe, in imitation of that of Hoffman from the vitriolic acid. See ETHERS. LITHARGE. Litharge is lead deprived of great part of its phlogifton by fire, and is in a {tate of imperfect vitri- fication. When filver is refined by cupellation with lead, thisiatter metal, which is {corified, and caufes the {corification of the imperfect metals allayed with the filver, s transformed nto a matter compofed of fmall {emi-tranfparent fhining plates, refembling mica; which is litharge. Litharge is moi€ ox metals with which the lefs white or red, according to the 1s called litharge of filvers a {ilver was allayed. The wht the red is called /itharge of golds : I Litharge VoL. LI has precifely t \ LIVER Litharee mavh R fil iveds of that whi af eealily revived into lead ; accordi in oid by ining gee 1s ing coals. reduce ay ined bY Sintufe with wil bh part of it which reft of the ethos good and faleable lead ro obtained various purpofes goof thefe refineries is fold ined. The ware. It is emp] otters ufe much of it for wir for and other extra oyed for the preparation of & azing their : remedies ; and alfo in we pias, y tO render of other fubftan ces. It h . as the other cals It has in general th monly ons Sates of ‘lead. All the lithar Yrs properties is more than is Ea Bees, The qa he Orne hot lent for the d med there tue HL See Reedy and therefore it is fults from the d IM O NY Li EAD. : tonation of. antimon iver of antimony re- of nitre. T : OI antimony with : yre pater reed i lee is then to be kindled Into a large crucible. T De i ; ; . he it has detonated e »and the detonation tob matter Wie, the ed, it is to be kept in fuf e made, When rucible is brok ufion and then cool matters are fi broken, at the bott ooled. Brie ear hich m2 be pad om cc ther oria, nearly of the {: € upper matter i Je¥ of antimon ie fame nature as the {cori 1s a faline y y. Thisisat : ie {coria of the regul mixed with . rue antimoniated li gulius Nuwar NTRP 4 of ne pyereoh lp hus > liver of anti > compact, red, and pearance h © of antimony. ’ animals ave bess fuppofed fimilar 4 a Salor and ap- PL vai ence it has received its ore of the livers of mony 1s principally compofed of the metalli c part of antimon : gifticated by Is Bale deprived of its fulphur, and dephle. © Some chemift » S i Heine liver A x 8 & metallic earth of antim aining part of fulphur and is thus reduced, rd of antimony as an anti- : i affirm, that it is only y melted, by means of a re- nature of wkich is Pras tuanison, I a fubftance the wixt thofe of anti imony and of glafs of anti antimon I one ftate, and fi ony. It may poflibly b : 0 : e . A Dietlyes in the other, wom fo formed ries in fufed. The true , : Jong the fire, and iors or lefs i; ‘tai : ature of thi efs we certained by a is fubftance ; : roper om may ealily be af- which wa proper examination. B . y al- Ss Con . , ut this fidered as important when s 235 Preparation; eme- dies LIVER introduced, deferves at prefent little notice. in what is properly called Chemiftry; Medicine, fince kermes mi- : have been ‘introduced, which are re- rior to all other antimonials from the certainty of their effects, when they are well prepared, and by which all the effects obtainable by any preparation of antimony may Pe obtained, by giving them {eparately or conjunétly in dif- ferent proportions, according to the indicatiorts to be an- fwered, See ANTIMONY, KerMEs MINERAL, and TARTAR (EMETIC). oy ; LIVER of AR SENIC. Liver of arfenic is a combi- nation of white arfenic with liquid fixed vegetable alkali, or general a ftrong difpo- by the humid way. Arfenic has in {ition to unite with alkalis. Mr. Macquer, in his Memoirs ‘1d of neutral falt, upon Arfenic, mentions 2 which refults from t I ic with the alkaline bafis of nitre, when nitre is decompofed, and its acid is dif- engaged in clofe veilels, by means of arfenic. To this falt he has given the name of neutral arfenical Jalt. See that arti= cle. d alfo by that chemiit, The liver of arfenic, mentioned 2 although compofed, like the neutral arfenical falt, of arfenic and fixed alkali, is neverthelefs very different from that {alt. The operation for making liver of arfenic is eafy and fimple. To ftrong and concentrated liquid fixed alkali, pre- vioufly heated, fine powder of white arfenic muft be added. This arfenic eafily difappears and diffolves, and as much of it is to be added till the alkali is {aturated, or has loft its s {till capable of diffolving alkaline properties, although it 1 more arfenic fuperabundantly. While the alkali diflolves the arfenic in this operation, it acquires 2 brownifh color, and a fingular and difagreeable {fmell, which however is not the fmell of pure arfenic heated and volatilifed. Laftly, this mixture becomes more and more thick, and at length of 4 gluey confiftence. = This matter is not dryftallizable, as the neutral arfenical falt is. It is eafily decompofed by the This does hot happen to the arfenical falt. Laftly, any pure acid is capa- ble of feparating arfenic from the liver of arfenic, in the fame manner as they feparate fulphur from liver of fulphur: ‘whereas the neutral arfenical falt cannot be decompofed but by means of the united affinities of acids and metallic fub- - ftances. Thus we fee that arfenic may be combined with fixed alkali in two very different manners. . 12 The action of fire, which feparates the arfenic. TI — ee re ee —— ee —= ————————— LIVER The author has gi id . hor has given to this ¢ TT : Sioer of jel; to diftinguith it RHA oy name of : avon fo a tation oF the name of the ior arfenical Sn ee e combination of the fixed alkali wi ” [alphur, LIVER ARSENICAL AL fulphur, ‘combination z (ul LPHUR. The liver of fulphur . liver of fulphur o De Ho alkaline matters. P Ordina ; AR ’ combinati : Rs SA be Bue either in the Ty kn fixed 3 {€ HVEY O ful phur by the ds J y. ; hn Sree fixed alkali and fulphur Hy ek Byyatom, quickly re to be put into a crucible, and el falphur A o avoid the diflipation and combuftie > oy jo the ‘falphtr is heat, however, is not neceflar ag the alkali. P When J els and facilitates the finon of 1 mixture is perfect! 3. Ye fo poused spon a greafed ftone, Ah Yin it4579 be is io acquires a brown color. Ifitbe re i” Fuse it 1s yet 2 3 ey en in pieces, a ot Hob . “he Pe . e wil 3 ‘ it fragly IAines motfture Pon he to Ne well corked, becaufe Yiquid ee fulphur in the humid way, concent ed toudtlic i and fine powder of fulphar are tob rated " es till the alkali has diffolved all that to be boil- ok Aen to be filtrated and: evaporated. an the Ds ing liver of {ulphur'is not much uf; i econd A Ci lefs advantageous than the Si » becaufe beet pn is an important combination ir7che 0 pounds iy general a very powerful folventy en try, perties bin ¢s, according to the ‘general elcpiofithe ee ‘tion. The ¢ be fubftances which enter initorits Soult i on, The fiber, by ‘its union with the alkali a a i oy efs combuftible than when alone ond appears and 21 z in So by the intervention of this jeisfln Billing properties. ie with fulphur, fhews lefs of its 5 fulphur 1S com em a s compofed of vitriolic acid 1 : may doubt to which of thefe its union ion, PAoRA os i © “is to be attribute ut i ibuted, But if we attend to the properties of liver of {ulph ks phury we fhall perceive that th is i hess fubipres combined with the alkali, ord fillphe » i ou principles. In fact, if we diflolve liver of AA ur fin water, 4 i is foluti , and pour into this {olution any acid,’ the liver of ful j i ulphur will be inftantly decompofed by this acid, which simll unite wi 1] ill unite with the alkali, and feparate from it the fulphur in 1 Hig oH a i: 3 LIVER but this powder, when dried d, appears to be fulphur, fuch as it was before. d which 1s contained in {ulphur be {ulphur is fneverthelefs fe- ia form of 3 white powder : and examine Although vitriolic act in general the frrongeft acid, the parated from the alkali by any acid, even by the weakeft, as vinegar. This phenomenon .c another proof of what we have advanced concerning the manner :n which fulphur is combined with alkali; for if the union of the inflammable principle of the fulphur did not confiderably oppof¢ the ad- hefion Which the scid of this fulphur is capable of contract- mg with fixed alkali, the weaker acids certainly could not feparate it. Thefe effeéts may be explained by this general rinciple, that the lefs fimple any bodies are, the lefs ftrong- ly they are capable of adhering to other bodies. The liver of fulphur exhibits alfo another phenomenon worthy of attention, and which depends alfo, as we {hall fee, on the fame principle. It is, that the connexion betwixt ch lefs in fulphur united to the phlogifton and the acid is mu an alkali than in pure fulphur. This is proved by the {nell of the liver of {ulphur, which is very ftrong and very fetid, even when it 1s not heated ; while fulphur not heated has fcarcely any {mell. This fmell of the liver of fulphur,, which refembles much the fmell of eggs beginning to putrify, becomes much fironger when it s decompofed by an acid. It is certainly occafioned by an evaporation of part of the phlogifton of the fulphur 3 for it produces exaltly all the effeés of the inflam mable principle when reduced into vapors or when it dif- engages itfelf from bodies without burning. It particularly affects the brain and nervous (yftem, and caufes {tupefac- tion, intoxication, {yncopess and when in large quantity 18 even capable of inftantly killing men and animals. Thefe are the fame cffedts which are produced by the vapors of charcoal, and of fubftances undergoing the fpirituous or putrid fermentations. Mr. Cartheufer, talking of the man- ner of decompofing fulphur with an alkali, to obtain from it the acid without [enfible combuftion, according to Stahl’s procefs, exprefsly remarks, that the vapor which exhales during this operation affe@s the head, and caufes ftupefac- tion. lknowa chemift who, when he was decompofing at once a large quantity 0 ¢ liver of fulphur by an acid, was firuck by the vapor {fo as to fall down and faint. Further, the emanations of hver of fulphur, which are duced into Vapor, and pothing elfe than pure phlogifton re which muit be diftinguifhed from the vapors of burning : I3 {fulphur, LIVER The author has oi iii ls See given to this combinati " Bro ii 5 AR om he mew ey lon o the name of the Jive entca LL combination of the fixed Lr iphr, a i” Ny ARSENICAL ob fulphur, ‘combination 7 furl LPHUR. The liver of ful far is'eh liver of fulphur ph phuy Wo alkaline matters. POrdin > 1: ’ combinati : hy i Sse either in the Ty wy ith fixed salt iver of {ulphur by the dry ¥i ey quickly aS 19, be put into a crucible. and (getiar. Filpin . avoid the diflipation and combuttio is to be the ful Nr rng heat, however, is not neceflar the alkali. Phe Salily melts and facilitates the fibon poticed Abt this mixture is perfectly fufed, it or fe PIE d greafed ftone, and then the liver ff to be kept dry and acquires a brown color. Ifitbe re ol ArirT kept dy ele icy broken if piece, nd pu wl : rioza ¢ which i . it any Yala motfture fromm ito be well corked, becaufe 0 : S : d Tiquid Toke Sig of {ulphur in the humid way, concent od too kali and fine powder of fulphur fe re rated . bs ery till the alkali has diffolved all that ' to be boil- wy then to be filtrated and‘ evaporated 2 ip the Tots 0 fale liver of {ulphur-is not much uf; cond shaw lefs advantageous than the orien eat ha fulphur is an important combination irehemi on 3 in general a very powerful folventy Bea perties Re es, according to the general edlepliich. op ‘tion. The ful full andes which enter into’ its Ob lott olzeoi ers) bps dion with the alkaline ns He combuftible than when alone ie appears ord pif Bieta oe ey the intervention of is wit " urate : - 3 Blips properties. ip Li i fulphur, fhews lefs of its ro o is gompand of vitriolic acid and phlogift TARY voaung whith bi Highs ito urdoty wirhs te fixed alkali Re ort ey uted. But if we attend to the properti ali its fib flancs urs we fhall perceive that the lpr id both its oe gambined with the alkali, and adheres 3 I all . in ey — = In fact, if we diffolve liver of ion {ulphus ill GL into this {olution any acid,’ the li Phur -will unite ih SaRatly decompofed by this acid whi o | the alkali, and feparate from it an in worthy of attention, an LII'VVE'R in form of a ‘white powder : but this powder, when dried and examined, appears to be fulphur, fuch as it was before. Although vitriolic acid which is contained in fulphur be in general the frrongeft acid, ‘the fulphur is neverthelefs fe- parated from the alkali by any acid, even by the weakeft, as vinegar. This phenomenon is another proof of what we have advanced concerning the manner in which fulphur is combined with alkali ; for if the union of the inflammable principle of the fulphur did not confiderably oppofc the ad- hefion Which the acid of this fulphur is capable of contract- ng with fixed alkali, the weaker acids certainly could not feparate it. Thefe effects may be explained by this general principle, that the lefs fimple any bodies are, the lefs ftrong- ly they are capable of adhering to other bodies. The liver of fulphur exhibits alfo another phenomenon d which depends alfo, as we {hall fee, on the fame principle. It is, that the connexion betwixt the phlogifton and the acid is much lefs in fulphur united to an alkali than in pure fulphur. This1s proved by the {ell of the liver of fulphur, which is very ftrong and very fetid, even when it 1s not heated 3 fcarcely any fmell. This fell of the liver of while fulphur not heated has {fulphur,, which refembles much the fmell of eggs beginning to putrify, becomes much ftronger when it 1s decompofed by an acid. It is certainly occafioned by an evaporation of part of the phlogifton of the fulphur ; for it produces exactly all the effets of the inflam= mable principle when reduced into vapor, or when it dif- engages itfelf from bodies without burning. It particularly © affects the brain and nervous fyftem, and caufes ftupefac- tion, intoxication, fyncopes, and when in large quanuty is even capable of inftantly killing men and animals. Thefe are the fame effedts which are produced by the vapors of charcoal, and of fubftances undergoing the {pirituous or utrid fermentations. Mr. Cartheuler, talking of the man- ner of decompofing fulphur with an alkali, to obtain from it the acid without fenfible combuftion, according to Stahl’s procefs, exprefsly remarks, that the vapor which exhales during this operation affects the head, and caufes ftupefac- tion. I know a chemift who, when he was decompofing at once a large quantity of liver of fulphur by an acid, was ftruck by the vapor fo as to fall down and faint. Further, the emanations of liver of fulphur, which are nothing elfe than pure phlogifton reduced into vapor, and which muit be diftinguifhed from the vapors of burning : I3 fulphur, LIVER fulphur, which are phlogifticated vitriolic acid ; nations, I fay, of liver of fulphur are eaf; body Capable of receiyi i to their nature and a expofed to the vapor odies, accordin mah €manations, bundantly, Iver, mercury, bifmuth, b f fulphur,. al] th efe pre- they would have been may be rendered vifib]e by liver of fulphur, or Y its vapor ; and hence liver of fulphyr may be fuccefsfully employed to difcover lead contained in adulterated wine ; and reciprocally, thefe metals, their folutions or calxes, (MINERAL), and Wing, We muit obferve, that in this a t pplication of the phlo- ur to moft metallic calxes, this phlo- {mitted either j mn vapor, o r by the fo inti- ? younger, who, in the Medical Gazette, pro- duction in form of a problem, as 3 ver great novelty. The chemift who replied, judicioufly ufed litharge to make this redu@ion vifible ; becaufe this Preparation of Jead being j s or {cales, which prefent furfaces pofes this re aflumes, when j of fulphur. All thefe p that the a i id, it may therefore be more eafily feparated from the liver of fu phur. The fmell and emanations of liver of fulphur thew, that its inflammable principle is continually diffipating. We may we ; thefe ema- ly applied to an €ving the inflammable principle, an ilver, for example, be ry, orif it be immerfed metal LUNA “enll fulphur, d into liver of fu rs {i 1 hur forme it is diffo ve ay therefore er particularly o” aid liver of ful- m Y dually ia if we prefsrve, y Iphur diminifhes > Reels rte velt . the air gradually changes : in an Op liver of fu phur 1n d more, and the ba, ¢ the | an ta. di tion 0 into vitriolated an planation. of ois ee of file We may fof 2 inciples.of fulphu ly a certain de- connexion > ppl tha oll Delis wy to each angry | if we fu by whic | 11 the phe- phur, 1 decree of force by wi fhewn by a inate degr and 1s even inc fecond place, which 5 yery phi if we fuppofe, in the [S08 upon nomena o ey logiton end orm or of combination. thet in falp 3 heir force of tenden inciples are either 1n- each other all their thefe two pri ith the alkalis Toon thefe fuppofivons, § a third body, 25 it leflen the ble of combining it, this ls accordingly appears to be or if they combine jon ; and this accor Ce Thich contract force of the former ph bodies are tang GATION, COM- fhe xsalon i See AFFINITY, AGG ! 9 fiyongeit uRion . ic matters; a ey and four Se folvent of ae in fufion. Liver of falphur pine, it attacks, ISR other metals. whica, oO olve gold more i Yo vegetable Sons 1 fogms £0.41 his compound dillolve he obfervation of Vir. Gop. This cording to the color ; and Seek by the humid war a {olution 1s of WA Gon, > be Rouelle the ¥ Tulphur has diffolved AAI, pure, as may when Eee of i deeper red color i al {ulphur in Stahl’s comes of am the making of artinc be obferved in be formed by the manner. 1 wlio “or of abforbent Particular The proper= nation of Thapeoper pis ph hur may ; car of thefe livers of fulp u not oars one 3 but A . + ivial which have Bey ought to be pi falts are glen icy are fixe c LIX1VIAL. AC jation, and thele 5. See ALKALI. been extracted by arn called lixivial [¢ on to the com= alkalis ; which TRNE A. This a or acid has in ge- LUNA CO e acid with filver. edly with thofe pitiiion of medio with metals, and pe Of thefefilver1s neral a great affinity or mercurial meta ol thefe metals 12 hite, or lunar, fcarcely diffolve: the called ot Marine acid gaa c y the chiet. Lv 4 it LUNA LUNA ius he ordi ; . rinati mine- aed ee hads. They ‘muft be generally much dj- convenient, for example, in the AL ey con- Yano Es Ju ‘be much concentrated, reduced into : ers "OF of any other liquor, eo, i Ne ruptitly Comat pd te with a confiderable degree of heat, toac- a re marine acid in whatever bafe it Pe & ® Fra left quan- Er oa This is particularly true as to filver : metallic bafes ; for if thefe waters omy pla. 17 ffi by. > when thefe metals are previouly diffolved tity of marine acid, a luna cornea wi Dep ol chit Jute a fHiniey i i o 5 the marine acid, which has a flronoer ) oy from a folution of filver in Ain X ’ i feparates them fram the fhe nitrous has, feizes them quickly, cornea is eafily known Oe new combination, Itrous acid, and forms with them a WATERS (MINERAL). that when the marine acid, which "To make this combinat We may cafily perce? in a bafis, it muft quit its In nitrous acid. To Te Bhs, it is firfk diffolved forms the luna HY "a and then the nitrous acid, : . ution marine acid, o : ] bine with the ; Fo : s Or more bafis to combi : ed fencaced, and iflolved in water, is to be which was united with the Lr A was . ccomes turbid, and in j : ‘fel f {ubftance with whiC : €lpitate j whi > joi {elf to the iu le from ly hi is formed, which has always the appearance of cy joins 1th TWO decompofitions take place, € lolution of falt is thus ad 7. pearance of curd. firlt united ; Ha ult. Thus, when luna cornea formed. "The preci us added till no more precipitate is which two combinations rc ult. : ’ a Hauor after the natant liquor LW when feparated from the fuper is made with a folution of common {a 5, ¢ A (alt with . >» 1s called luna corn : ! : fome cubic nitré 3 an nd Marine aci £ ration contains 10mMe¢ Cu 1 d, in this , é acid has fo great an afhinity with {jl : ope bafis was ufed, it would be transformed, overcharges itfelf in f ty with filver, that it an earthy bans ’ he bafis Prt. o ome meafure with the metal in this operation into a nitre with an arty ai oa _ Precip } 0 : ’ \ atl iver 3070 the combin :na cornea 1s much lefs' foluble in water The beft method of feparating " a cornea, is to mix Tittle ras ations of other metals with this acid. Thi or. as the chemifts fay, of reducing luna Ire Br pn . © lolubtlity of luna cornea is the caufe of its : Wl a elb rely. and to melt it in a crucible v in the form of a precipitate auic of ts appearing 1 it very accurate > ; e fixed alkali: but the heat muit be The ad : o s ve quantity or iom Ce 1 {welll hich a he adhefion of the marine acid ith: fiver ic large quantity lied till the ebullition and {welling, whic In luna cornea.” If this with iver is very ftrone very gradually applic od alkali and marine acid, acid Carries o 11 this matter be expofed alone to fire. the are caufed by the action of the fixed a Joli tn or So t a it a portion of the filver, although this Ne ceafed ; then the heat is to be encrea os Fh found tikes the Pe ry ixed. The remainifg matter melts and : is to be thoroughly fufed 3 after Ch {itver is wuftly na a a ib fubftance, as all chemifts fay revived at the bottom of the gruchie ay orion wr jcc thas been called luna cornea. § 3 : & of all, when the 1evera a TR . a cornea. Somediff be the pureit of aii, 1 occ : : : ifferenc ed to be p . ~afily be Vesarn combining marine acid with filver. nd os She. But the luna cornea quiet Big ‘ ai e 1 - . 3 dl - ~ * $n “3 3 ¢ the nr ¥-19 Wael it 1s done, and particularly Second : ; ced without lofs; becaule it 18 apt to rap DE, : aon or Ihe two Lubllmges 3 x d even to pafs through crucibles. See AciD (MARINE), “,Uuna cornea is Ly } an arts (y ) ; and © not employed either in medicine or in the and SILVER *. LUTE. Patil : s even little ufed in chemiftry, excepting f; | “af operations and refearches. This preciniatic, OF is by its arine acid, : 1 {~ roy beft “ -ments to difcover the b , : ' * My. Margraaf has made experimelis is 5 = vee Sppuaancs; > be o luna cornea, wiici he found to be th brafs, gives a filver.lik ea-falt and tartar rubbed on method of reducing CC lver in aqua fortis, Pre: ployed: for the Alor Prestancy 3 and is the fubftance em lowing : Diffolve half an ounce of pa oki a ats, PL . . ’ 7 n . : & ow o fubflantial fj] g of ithe dial-plates for clocks, A more cipitate it by {ea-falt, an dn c Hho preg, an of a ors wins, Jf the then weigh five drams and fixteen grain : Ivering may be oi oe given £ olatile piece of brafs to be Pil RO and a half of dry vo lv 5 $ all n ounce anc F) ered be previoudly heated confiderably, this precipitate, mix it with a little water peration be repeated {al ammoniac, triturat and cleaned with j f; 1 ether with ” a {cratch- : well together V ! till the filver feems to be brat, and #1hs0 ; 2 Sher ve WF three ounces of mercury potion 1 i ently thick, The brafs, having during a quarter o i 5 a of quicklime, and continuc to f With the marine acid than the filver obtained from cinnabar DY 2 little more water. Thus an a tronger as, feparates thi i , ’ 1s acid from the fil ich is 43 " : n= : ‘1 {ome hours with . upon the furf; ver, which is then precipitated ] triturate during fome rbd sathed from a white if ace of tl nl: P tate 3 ing ee ing walhe ! of the brafs plate, Plated amalgam will be formed, which being powder very LUTE any chemical Operations, mething to preferve them fr of the fire, from being broken or melted exactly their joinings to each other, which they contain, when they are vapor. For this purpofe feyera] matt in general utes. LUTE. Inm required thicknefs. The fand mixed with the lay is neceflary in this lute, to prevent the cracks which are occafioned by of clay during jt the contralting s drying, which jt always does when jt is pure. The hair ind the parts of the lute, P it applied to the veffe] : ftanding the ks are always ferves alfo to b and to kee fand whith 1s" introduced into it, fome crac formed, which occafion pieces of it to tumble The lutes with which the joinings of veflels of different kinds, ac cording to the nature of to bé made, and of the veflels. When vapors of watery liquors, and fuch gs are not cor rofive, are to be contained, it is fufficient to furround the Joining of the receiver to the nofe of the alembic, or of the retort, with flips of Paper or of linen, covered with flour- pafte. In fuch cafes alfo flips of wet bladder are very con- veniently ufed, "hen more penetrating and diffolving Vapors are to be contained, a lute is to be employed of quicklime flaked in the air, and beat into a liquid pafte with whites of eggs, This pafte is to be fpread upon linen flips, which is to be applied exactly to the joining of the veflels. This lute js ver convenient, eafily dries, becomes {olid, and fufficiently firm, owder and dried, will weigh three ounces and half a dram, y diftillation of this amalgam, a refiduum of filver, four grains lefs than the original half-ounce, wil] be pbtained, By fubliming the white powder, which weighs five drams, three grains of filver will be obtained : byt if the am gether diftilled algam and w > the operation wil fail, and recompofed. Sz Bery gn Mem OIRS, 1740. M. Beaumé fays, that luna co rneamay be reduced without lofs, by fufion with four times irs weight of fixed alkali, Laftly, for, notwith off. hite powder be to. the luna cornea be the veflels muf} om the violence » and alfo to clofe to retain the fy bftances volatile and reduced to Crs are employed, called ied Ad afte fome drie , e forming into a p contained, W :s made by lute. T a filken fearce, an ed through a pi this pafte clay finely powded;) iin then by beating . t ’ moiftencd Wi el d fit . , diffolved in it, an well in a dered drying by litharge es and re- f painters. This lute eafily tak {fe o for the u ied, b be applied, by : hefe are to tains the venient fize. T ders of a con flattening them, {tick on id enough to ot become folid enoug el s foft, and does n main J are clofed, are the operations fubftances to be diftilled in thefe MADDER be : apors are to 1v. when faline, acid, and Bo ute called fa en ecour Laftly, w ft then have r mu y : il which 4 . d oil, that 1s, ol ith boiled linfee mortar with oo I g ght flels, which eug soinings of the ve 1d prffent , to Deyo leaft un esl pif cod rfectly dry, When the joie from adhering. 3 Thefe . f eggs. 1: nd whites 0 cond lute ith lute of lime 2 thread. The feco Jinen fpread With BES Oo packs flips are to alone. ino of . fteeping © tion is the a N. Macera netrate, ACERAT 104 liquor, to fofean gene of them. bodies ai to diffolve fome Bi eftion, and only open them Pr effentially the fame A the heat of the Thisoperasion 128 ypqijfesno Mars 8 digeftion, when- differs in ee is preferable ation. For inftance, simolpnas, felefs or hurtful to gua - matters are to is ever heatis i dy aromatic veg them, to extrac and woody ften and open ? il, they when hard e tion to {often ¢ . ential oil, th inten hem their ellent 3 cons fteeped, wi afily from t ot digefted, pliowards macerated without heat, ig diffipating a great ) m 3 able ji! re~ Og fo be the {malleft heat 3 gap ucht always to be pros enng iri etor, W 1+ ameliorates the part of the fpissses 2 poffible, fince it amelio {erved as muc | 4 : itVe | oil, and encreafes its quantity ! 2 MADDER, (z) MAGISTERY, . rater with The root of madder mgrogna®s vg This x) MaDDER. d fpirit of wine with a bint tinges their a dull red color, . mal along i i red. Wool, pre- root, when ea oft folid bones, of 2 urine, and their m 1 an ’ i ' y ] MAGI STER Y MAGIS TERY. €ipitates, Thus magi ynonimouys : but late] Precipitate, apd, pplied that ¢ Precipitates op] i ame is given to almof all pre. {tery and precipitate are frequently y chemifts have chiefly ufed - the term cular fiery to fome- parti Ys Wh a arts, Such i that femi-meta), one, and wel] wy tion, very pure b > Which muft af; e magiftery of feparated from the thed, i{muth muft be dif. b € very pure. To anuty of clear water Is s formed, the fediment y and more Pure water is to be comes off qui id. The fediment, which ty of bifmuth, ought to be Carefully dried, ang awell clofed bottle, 1s the magifte kept in hot decoction of m but not a very beautiful red color , Mr. Margraaf (Berlin Mem, 1771) thews how a very durable lake, of 1 fine red color, fit for the purpofes of Painting, may be obtained from madder, The procefs is as follows. Take two ounces of the purelt Roman alum, (French) quares of difiilled wage Set the pot adder and targay 5 very durable, glazed pot. to boil, wi; madder, the fire, on t hdraw it, ang adc Beil the mj : and filtrate jt ¢ r of paper nop colored. Let the liquar thus fy “ land a night go fettle ; ang pour off the clear Liquor into the glazed pot, previoufly wel] cleaned, Make the hiquor pot, ang add to it gradually a clear {olution of falt of tartar jp water, till all the mag €r 1s precipitated, trate the mixture, and upon the red precipitate which remaing upon the filter pour boiling difiilled water, till the water ne longer acquires a fz]; tate. The red lake is then to be gently drieq, No other water, neither river nor rain water, produces fp good 2 color as that which has been dj © quantity required of this js confiderable, ‘The color of ¢ '¢ precipitate is deep; but if two of madder pe Ne part of alum, the deeper: one Part of madder and four pay beautiful rode color, ounces of the h Xture once or twice 3 hrouph a double filte rated {ia filled, and th parts color will be itil} ts of alum prodyce 2: Bifmuth MAGIS T TR bftances which are ' ¢ thofe metallic fu with much i +i¢" one of tl lution : trate . Bina oS > i aids by but by os inion ly fepa be kept di id is more than is | PE hich ¢annot Ee i acid 15 Mm of the acid, ther, an certain point, o> By the CO 1s Very white ’ (avirate: the I ormed Se united wish on ye is'pe soniof acid r comife the nitr eration y “Hortiono oC a becauie y he a finalbper take from ya phlogifton. forme BC c cinth mo ties, fo which the water bifmut roperties, which:the v from the in many of its p on falt taken lead in many OF1Y n of comm acid his Lo refombleblend: ing a folution hite pre- 's bifmuth x atiby mixing @ 19 acid a whit a onions He inthe ES folutions of hve c tic : happens _to iol he mari : {olution nich alfo hap ipitation t with a ic ed, Whith 2.70 Bis DO hirsauthai ah . 1S form ? hat in tnt d a bifmutou . cipitate d7 believed t d forme : If of this : 1 th, an sen himfie and of lea with the bifmu sigh he had been hi ely by . ted wit ¢, although ‘on is caufed merely acid un Pott, although, itation 1s caul d; fince, But Mr. hé precipita is diflolved ; . os has J common fhe fo {alt contain in 7 . 1 . CO . 3 BN # water in whic of bifmuth and o no ‘precipitation ir when the A quantity of aati; SEs eter left poflib Bifmuth, tf ; the {mal ir mixture. . ter into rom their mix ect. is to ente uf ee ae ery Os, It rye a hief ufe o to Daint ufed by 7, its luftre, “Ihe chie hite pain ior beaury, . the compofition Oka from its pe which renders 1t 11 other wt int of carnation, ferred to 2 {t infenfible tin iteft kin. . ter- n hite coun an almo {t and w ; eoreat, 18 E ne fimilar to the faran i fin io faid tobe pv : oe, in iE. VE This avant ? faults: : ie ule of it; 1c 1S anys balanced oy bya Sonus Yor Metallic fu sated 0] ackifh color. be impreg {iderably Po < a blac rapt to Sy ADOT re be very apt to b 11 Vapoi, to acqui known to 1 while it is 2 apt . Ixes are Kno hes them w ; . By this d their cal when it touches -ombination. I with phlogifton, whe favourable to oR the phlogifton oF omin Any other they peeover ‘a phil they ne means, yhether been deprived, o dale and blackifh pir which hey ic they always uth is one of thet ind : antly, hat ot Dil s brown, @ uperabun lic calxes, t hite become he HRlo fps of all metihie Feit its fe ofition to tae ee fufceptible of ea) 9 by a very flight od houfes of aa > bts - ur, .aden-colored, xhalations Fiver of fulp even lead {uch as the ex from Tv st in well giftic vapors fie and puis muft be rE rculatng 2 ’ « ir hi by ci St ee en a e injured by ¢ For this reafon ewan it would be inj From this property, clofed bottles, i paper coverings. : hich pervs vapors Ww : MAGNESIA it from i {c 1 i y » . But this method AE, . does not cipitatio produce fo ar Beton by Jo Hone. The 5 yom x ies 8 the pre- Alkalis ho very eafily reco . 18, that : ME always contain Neet is phlogifton. which are na apply it to the m perabuifes: muth, which be Saag \ and particulatly 10 aie kaluss greater : es more brown | alx of bif- So Quantity which it takes of Chie nora kosthe MAGIST ‘ammable matter. &c. Coral, TExY of CORAL, CRABS-E itances of that kind yes, pearl, fhells, chalk d -EYES, eafily foluble in ag aye all sbiorben and Oth Withan earth us acid, with whi us earths treated like di If the Jos Walch 157 for a titre other-water of nitre; that os tars be ? » "1 they are precipitated by a fixed alkali Sl this rig Slketi, ond afterwards well wathed name 1 i of magiftery is then given in a very divided ftate v oT i them, together with ow een diffolved and precipi- nothing elfe but abiorbant puns of the {ubftance which has + All thefe magifteries are earths, which diff 1 i 3 8 ; 1 “ little from each other. o from m g of Fo he method of pre aring thefe regio yi P : s fee MAGNESI A A A precipitated from th LBA, Magnefia is 2 whi mon falt by a fixed alk motagiwtess of nitre ea] Srth edulcorated : ali. t ought af of com- [seen deprive it of all the rio: tl well To make magn $ It might mon falt, is aga, the mother-water of nitre : Eduiabls quantity of % Jarge veflel, and ilu och ol alkali is | ommon water ; vith a.cen- a poured upon it, and ae a liquid fixed milky color, I prefently becomes: turbid mixture is to be fereri So ie this manner alkali is rnd of a white ceflary for facilitati with common water. if 5 iquor ; t g . ‘that b ment is all f, ing the earthy fediment : w be: ne- heey 8 Bred, ENA when shis fodj- by a cloth : ks upon a filter of brown He from it : jt capable of givin water 1s poured upon it rE fupported g any tafte to the water - ? the an i dongee ; IS then to be “pe formed into troches magnefia. of nitre and of common {alt entirely compo earthy bafes, an See Waters (M Basis, WATER of the SEA an (CommoON), with EARTHY BASIS. Thele with 2 therefore do remaih diffolved 1 more cryfta MAGNESIA or cakes, and left todry. Thisis are almoft fed, the former of nitre and fea-falt with d the latter of fea-falt with an earthy bafis. oTHER), NITRE, NiTRE with EARTHY d SALT FOUNTAINS, SALT he mother-waters SaLT (SEA) i d marine acids faturated deliquefcent. They not cryftallize ; and great ‘quantities of them 1 the laft portions of liquor from which no Fixed alkalis being capable arthy bafes, and of feparating in the prefent operation. el{e than a very much divided cal- in medicine as an abforbent th, and are very ls can be obtained. all falts withe of decompofing ually feparate itin t their earth, do act Magnefia is then nothing careous earth. tis employed earth, and isa very good one, from the finenefs of its parts- The mother-waters from which magnefia is to be preci- pitated, muft neceffarily be diluted in a very large quantity of water, becaufe the abforbent earth diffolved by the nitrous and marine acids is there in fo large 2 quantity, that when an alkali is added to it without dilution, no precipitation feems at firft to take place. The molecules of earth, not being capable of moving freely, and of joining each other, do not form fenfible molecules, and remain almoft in the (ame ftate in which they were when they adhered to acids. But the feparation is neverthelefs made, and fo copiouflys that the water of the mixture is found to be in quantity, and that the whole becomes {olid. folid coagulation, which happens when two very quors are mixed, aftonifhes perfons who do not underftand the reafon of it. It bas accordingly been called the chemi- cal miracle, miraculwn chemicum. 1 o prevent this coagula- tion, and to allow the earth to depolite itfelf, a fufficient quantity of water muft be added. After the precipitation is made, neutral falts with bafes hich differ according of fixed alkali remain in the liquor, W to the kinds of acids which formed the falts with earthy bafes, and according to the nature of the alkali employed for this decompofition. Thus, if the mineral fixed alkali had been employed, the neutral falt formed in the mother-water 0 fea-falt will be common falt, and the neutral falt formed by .that alkali in the mother-water of nitre will be cubic nitre. If a fixed vegetable alkali has been employed, from the mother= MAGNE SIA mother-water of common falt the febrifugal falt of may be obtained ; and from the mother. only that febrifugal falt; but alfo ordina tained. Hence, if magnefia be ry-large quantity, the water, after the precipitate has been procured, ought not to be thrown away ; as from it much good nitre and common falt may be obtained, according to the kind of mother-water employed. To obtain nitre, fixed vegetable alkali ought to e ufed ; and to obtain Common falt, the mineral alkali: the liquor is then to be evaporated, and cryftals of thefe falts will be formed, If the magnefia is not wathed falts. In that cafe, it would not be 2 imple abforbent, bug would partake of the virtues of thefe falts. . It would even ¢ purgative in a certain dofe : but as the quantity of falts which remains is always uncertain,” when we intend that the magnefia fhall contain any, it ought to be prepared in the ordinary method, and afterwards fuch dofes of thefe falts as we thall judge proper may be added to it. Some artifts prepare magn alkali. Their method js b and calcining the refiduy acids: but this method calcination acquires ‘the If, iaftead of pouring ry nitre may be ob- made in a ve » it contains much of thefe efia without precipitation by an Y evaporating the mother-water, min a‘crucible, to diffipate the is improper, becaufe the magnefia by property of quicklime. fixed alkali into the mother- vitriolic acid be mixed with it, and if the mother-water has not been diluted with commion water, a large quantity of a very white precipitate will be formed in it. Some authors ave improperly called this precipitate magnefia; but itis of a very different nature from the earth properly fo called. (@) The water, (2) This fubffance from the dark-colored mineral called alfo map nefia, has been accurately examined by Dr. Black. of that excellent chemift on this fubject, vol. of the Lfays Philofophical an burgh. - From thefe we learn the following refulcs : is foluble with effervefcence in vi acetous acids. With vitriolic ac; ; diftinguifhe d by the name magnefia alba, Cr mang any joy , $ The experiments are related in the fecond d Literary, pablifped at Edin 1. Magnefia trioli¢, nitrous, marine, and d it formed ery tals fimilar in all . relpeds to thofe of the fult called Zpfom-/alt, "With nitrous acid it formed cryftals which deliquiated in a moift air, With ma- rine acid ie did not form cryftals ; but the faline matter being €Vaporated to drynefs, foon deliquiated by expofute to air, With iftilled vinegar it formed no cryltals by evaporation ; but a faline mafs, Sylvius on 1s ure calcareous earth, ¢ water of nitre, not. being 3 P za | confitence, and whe with acids, whence MAGNESIA MAGNE LA al fediment formed by adding vitriolic acid, The fedim vhich Gifts of that earth w this . in color :r:d. refembling glue 1n CC 5. Tc, Shen Ty was ie 5, By ccna, 7. of its weight. . When T I Re einaion was Seay it loft o! bftance loft by © ioht Io it loit vx : ihe fibge and almoft all He d, a od as or fixable ih ed .to it by folution oh; the gas of which calcination, was ra by a mild fixed alka Ee Ges (2) it feemed ‘precipitation from. § “the {aft mentioned Pom thefe earths, 1n it abforbed. 3. hw earths, but differed ids (1), and alfo ir suslogous (0 alts formed by it w Ith = even when calcined, the nature of the but efpecially in this, 38 of the Dictionary, other properties He in water. The Aut arth ; this name be- it was not folu erly calls it 2 calcareous, BItY Fle into quick- ‘therefore, 1mprop Gi % earths only as are by volatile alkali. 5 ing Bpplicatle » precipitated from acids by h from acids. lime. 4. ItW pita areous earth - calcined, it recipitated calc did not preci: ‘When un BY t eprived of gas, it d reater : erwile deprived cids is not grea When ciicined, 9 pnb its attraction Fe oe former precipita- pitate thle hel arin ; but the caufe vhich tended to join the than that of Se oe he fum of the forces wh . 1 tha tion was this, th nd the magne aonefia, and t calcareous earth with the gas of the m 8 : hich im of the forces which : as greater than the fum ¢ id, and the mag. with the acid, wa rons earth with Be i with gas, tended to Len he 6. When uncalcined, niefia with the gas. ©. 5 . that the ater : which fhews, th he 1 Tie lime-water ; W bine with t it precipitate is gas d. fince the former garth tock i 5 : he y ! which means the format EE : from the latter earth ; Yiwuh 3 achire va pp. hi ie ny gg ed to Dr. Alon o re the putrefaétion This property fugge adding magncfia to water, fhe p refation fiveet water at fea, y ented by the previous gadislen of GREE. he. By dicen a the Soraon of atile alkali, were RY ining fome {mall por * water, containing aS Se nn J 0g, £500 ip WL TH of Epfom’s alt is hie a fran orto Lie do Lon Normeay, is there combined firatum of coal at 11 pi coal).- The magne 1 Is her « any oy joyelope A upon calcination, 2 q oe hie red ir, 1 1 examines Bc is formed. xcellent memoir, 1n Whish be on Moe fe A carths in Saxony, diico nature of the ferpentine Ra contain ESgReia. x YoL. . MAGNESIA this acid takes from the nitrous and marine acids, and forme Lp TK 41 . . ~ . “ys . . | ia NET. (¢) . . i ie S beef ‘riade with jt a iclenites. This felenites appears as a precipitate ; | MAGN The grain is fo telied nich has becetiie fit becaufe, as it is very little foluble in water, it cannot be al] eS and afterwards dried, fo aking beer. "See é fermentation, or for ma he, yeh fufpended or diffolved in the liquor: but if a large quantity £ EE fpirifuon ak A of water, efpecially hot water, be added, this pretended a Faken cil) arid) . 1 URIBE TD : Jaonefia Shite does not appear, or afterwards difappears by pe BE ANN A. Ser Sucar. | QUIT «being again diffolved. ‘This recipitate is not appiied to any Es . (4d) A oiven ifs ‘ufe, 2 See SELENITES, DT be y MA +2 This name has long bee MAGNESIA. (4) a nal foriafariinesily] soars Oy | 3 femiometals. Lately it feems to be co dhe .... M. Monnet fays; that not only all the ferpentine earths which ; oneal to apply it only to were EE da he has examined contain magnefia, but alfo all the marly earths, Ms. : {arly formed. This feems to be better ambi and that by treating thefe with vitriolic acid, an Epfom fat is i d indeterminate fignification, from t tod aol Produced : He fays, alfo, that a great deal of Epfom falt is ta vague = ity ‘which might thereby’ be introdu : Cryftallized in the” alum works, and that all the alum éarths do uity and obfcurity whi ! allo contain magnefia. The fame agthor alfo pretends, that this ee PYRITES. earth is alfo to be found in the athes of plan ts, together with the MARLE. (¢) LACT Ton pr MIRE MARS; calcareous and argillaceous earths. He thinks that thefe earths EE iy Are produced by vegetation. pe oy ; which a confiders Magnefia obtained from the mother water of ¢, by expofure {¢) MacveT. ‘Magnetsare ay SH fays; that they to fire, was changed into a white opal-colored glafs (which after. able portion of iron maybe “ isie-of mitre. and partially'in the wards became tranfparent) near the fides of the crucible, and the are almoft totally foluble in {piri Is Lid M vitrification ‘was advancing towards the ‘middle. D’Arcet’s vitriolic and marine acids. ; fones are fo called, which Mem. I. p. 26. : (4) Mararss; Allthofe SaleapeguRones capable of regeiviog (4) Maenesia Nicer A, or Mancangss, is commonly con- ; are hard, which have a Sompact textes “as-beautifuls Far thei idered 2s an ore of iron ; but the experiments of Mr. Pott and a fine polifh, and which BE on SLi Sa ol) 8 r. Cronftedt thew, that this ftone contains little or no iron, and properties, fee EARTHS (CaLcar © oF Siferent proportions 0 therefore the latter author has made 2 diftin&t order of this earth, (¢) MarLE is an earth compofed | Marles efférvéfee” with which le calls terre magnefie. Its colors are dark-grey, ‘black, argillaceous and of calcareous 4k the calcareous earth. They red, or white, Its texture is ftriated, or with concentric fibres, or acids; which property they receive of thefe two earths are. By a indeterminate, It has the following properties: 1. It does not are fufible by fire, as all Pirates redominates,. they are galcin= effervefce with acids ; they, however, diffolve fome part of it, lefs heat, if the calcarequs ei Spree if the/clay predominates, efpecially when ‘it is calcined fpiric of ‘vitriol acquires from | able into a kind of quick lime ; and maffes capable of ftriking it a rofe color: aqua regia alfo acquires color, efpecially from they may be changed by fire into iia the black kind. From thefe ‘folutions fixed alkalis precipitate | ignited | arks from feel. rehend under:this name earths a white earth. 2. A {mall quantity of this earth, mixed with a - Some authors, as Dr: Hill, camp and which are. altogether ar< glafs frit, gives red or purplifh colors to the glafs, . Larger that contain no calcareous partic boy ropesly confined to fuch com quantities of it are added, when a deep purple glafs is required. : gillaceous, But the word A PR earth, . Therg may It is alfo ufed to give a glazing to pottery. 3. Fufed with nitre ound earths as confift of clay d other earths intermixed. The or with fixed alkali, it g1ves to warm water various colors, green; be occafionally fand, talk, am nd calcareous earghs de alfo differ purple, red, or blue, which change by a itating the water, proportions. of the argillaceous and BRE ‘ronfledt affirms, that it deflagrates A ue : .and properties, nitre, Pott fays, if much. Hence a great diverfity of the appearance.and prop does not, $+ Cronftedt fays, that he has fometimes extra@ed of marles. Marle is much ufed in agricyipure to give forulity a fmall portion of tin from magnefia. 6. The fame author affirms, to foils ; and this it may do es of land, or byintro- that the colors given by magnefia to gifs are eafily deftroyed by which is known tobe a pe wet ity into toa light and. fandy foils, calxes of arfenic or of tin. Whence does its property of tin ing’ | ducing a certain degree 0 ENR ig the principal pabulum of lafs proceed ? Does it contain any of the known volatile metal. by which means the water; Ww. too faft by evaporation. For i: {ubftances, or 3 new femi-mergl ? oY Sh gate is prevented from Raping this ~ i MEASURES M@ RCURY : " MAR S E he fats i] a planet which chémifts havé givén MENSTRU UM. Menftruum isa word fynoninious iron, and which is {till r : in gtigdicine 4 ; Uh lvent. See TION. fia Pha Se te ! much ufed jnuiglicine and che- with foleetu gee Bok is the name of 2 planet, MASTIC, (fo iio hich is alfo given to the metallic fubftance called quick- MATRASS. ~ A matrafs is a bottle with a neck more er But as mercury is the moft general ‘namie, oe {ube or lefs long, ufed in chemiftry for making digeftions-and ma- here relate the principal propersies of . this; metallic: Albe cerations. Matraffes are alfo ufed as receivers. Their form france, : ah bite ape is different, fome of them being fpherical; which is the | "Mercury is a metallic fubftance of a fhining i ep ordinary fhape ; others flattened at the bottom, called mas earance, entirely fimilar to that of filver, It is hab! 0 red | traffes with a flat bottom; and.others having the figure of an | fuid, and confequently we cannot difcover either 1ts GASH a egg, which laft kind are called philofophical eggs.. Thefe 1 lity or the tenacity of its integrant parts. yo i i; - matrafles are chofen according to the operations intended. Its fpecific gravity is very great : next to gold and p 3 a | The moft convenient of all, when we do not mean to ope- :t is the heavieft of all metallic fubftances, 8nd sysA he | rate on a large quantity of matter, are bottles of thin glafs, | known natural bodies. It lofes about y's part 0 its weg | known by the name of medical phials ; becaufe thefe phials in water ; and a cubic foot of mercury weighs 947 pout jane] | are very cheap, are made of good glafs, arid may be quickly Neither air, water, nor the united ation of thele wa heated, fo that the liquor contained fhall boil without dan- s. appear to make any fenfible impreflion upon m $1 i : on | elements, app ft than the perfet me= = ger of being broken. This advantage they owe to their cury ; nor is it more fufceptible of ruit than pel 1 | thinnefs. Such phials are very ufeful ina laboratory ; and tals Its furface tarnifhes, nevesthelefs, toa 6ciS egtee; therefore a number of them ought always: to be kept there. and more quickly than gold and filver, when it is expoled 53 See VESSELS. : the air : but this is becaufe the duft which floats 1n the aie MATRIX. (¢) quickly fixes upon its {urface. The watery vapors allo : MAT T. An ore not perfectly deprived of its fulphur, | which float in the air feem alfo to be attralted by the mets when fufed, is called a matt. Itis obtained in the firft fufion cury. ous for the extraction of metal from fome ores, = See SMELTING Mercury may eafily be cleanfed from thofe extrane G ef ORES. | matters which adhere only flightly to it, by making ’ pas MEASURES. (5) , through a new, clean, and clofe cloth, and afterwar y y MENSTRUUM heating it. When mercury has been thus piste i 1s : ] : : Tt vis free from all metallic allay, 118 copfiderably Bai eng this latter purpofe clay alone may be ufed in fuch lands with con- phofphoric light I produced by fale ing or rant parts, like fiderable fuccefs, Males are fometimes foft and fometirnes hard, mercury contained in a barometer. 168 INET0 E) Tipp like flones or flates, Generally, they crumble by expofure to thofe of melted metals, feem mutually to attract ea ? amr. : i, I" iq : . -meafure, are to the meafures (1) Mares iro snc tly lle in fis of win The galln, aur snd in, lel but not at all in water. It becomes foft and tough, like wax, by being chewed. It is ufed as an ingredient i ifhes. #31. : ; i _ (g) Matrix. Fhe matrix of ores is To cathy and ftony The French meafures of Quantity ufed by chemif, JubRances in which thefe Siesallic mater aregenerally inveloped. i mil is equal w0 oe Dopines e are very various, frequent! , quartz, fluors, or horn~ . es Te : fetier blend, we note to te aril Os A pen oe The shipiee : Wa two Seite pf Measures. The Englife meafure tit ; he demi-jenier TT : : ter at the to the following table, BI witfene 7 4 ug sending ‘The poigon igh fase Pa Ry Sil a be Eng+ One gallon, wine-meafure, is equal’to 4 quarts froveie poist, The propardon of the Pan 7 One ont” aimbot 3 8 2 piss . 1] As bie nib fures of ength, it is fuflicient to oblerve Bere, wat . gy Aye Ho the Paris foot is equal to 12,785 Englifh inches, or to 182 gl } The : : oot, as 114 tO 107. : AGEL £ f K3 & a » Retake of Preceding Frame | MEASURES M py’ be 3 : : ARS is the name of a planet which chémifts havi givén to iron, and which is ftill much ufed in medicine and che- miftry. See Iron. ; Mas TIC. . ; TRASS. ~ A matrafs is a bott nk ; bottle wi > hs long, ed in chemiftry for aki ek oor poretions. arralis are alfo ufed as receivers. Their form or is ome of them being fpherical; which is th lig pe; others flattened at the bottom, called . py Sita {oot bottom ; and-others having the figure oo” $8, Wh 5. i kind are called hilefaph cal eggs. T hefe Bueller chofen according to the. operations tended. he Hg eonveaiens of all, when we do not mean to er leone ie quantity of matter, are bottles of thin Ia 5 pow 3 : name of medical phials ; becaufe thefe Shial . RIS very 3 ; 2p, are made of good glafs, ard may be Fickly ed, Hot y the liquor contained thall boil thas da y Be 8 Jroken, This advantage they owe to thel ; shinngis. ; Sanat Fels, ore very ufeful ina laboratory ; and gy m ought always to be kept there. Esa lait Ade not perfectly deprived of its fulpbur, ee ed a matt. Itisobtained in the firft fufi n onof metal from fome ore in of Once ores, See SMELTING MEASURES. (5) MENSTRUUM. this aster putpofe ley slone miy be ufed in Tach ands with i a» ats are fométimes {oft and fometimes hard; sy ; nerally, they crumble by expofure to “(f) Mastic is a refin almoft totally ol | 1 totally foluble in {piri i bot ker. boomer fd cng ike ws, ‘ ed as an ingredient i if 4 fo $2 Maren. The matrix of ores is ts d fto Thefe are Thy calic matters ate generally inveloped | bons Fin note to the rind Or 8 fers Si Huns) or ord Measures. Th , afi i a to the following table. Eagile waafimeif funity ie dectriibng ne gallon, wine- is : Ea Yan Sopa Yu p iaileeltaind 28.835 cubic inches. . The Mg RCURY _.MEN STRU UM. Menftruum is a word fynonirous with folvent. "See SOLUTION. MERCU RY. Mercury is the name of a planet, which is alfo given to the metallic fubftance called quick= Gloer. But as mercury is the moft general namie, We 1 here relate the principal properties of this metallic fubs ftance, Mercury is a metallic {ubftance of a thining white ap= earance, entirely fimilar to that of filver, It is habitually fluid, and confequently we cannot difcover either its ductir lity or the tenacity of its integrant parts. eh Its fpecific. gravity is very great : next to gold and platina, :t is the heavieft of all metallic {ubftances, and even of all known natural bodies. It lofes about part of its weight in water ; and a cubic foot of mercury weighs 947 pounds. Neither air, water, nor the united ation of thefe two elements, appear to make any fenfible impreflion upon mer= cury ; NOF is it more fufceptible of ruft than the perfect me= tals. Its furface tarnifhes, neverthelefs, to a certain degree, and more quickly than gold and filver, when it is expofed ta the air : but this is becaufe the duft which floats in the air uickly fixes upon its {urface. The watery vapors alfo which float in the air feem alfo to be attracted by the mer= cury. Mercury may eafily be cleanfed from thofe extraneous matters which adhere only flightly to it, by making it pafs cloth, and afterwards by # through a new, clean, and clofe heating it. When mercury has been thus purified, and is free from all-metallic allay, it is confiderably fluid. phofphoric light is prodyced by fhaking in the dark fuch mercury contained in a barometer. Lts integrant parts, like thofe of melted metals, feem mutually to attract each other, ale-meafure, are to the meafures The gallon, quart, and pint, refpetively, as 282 19 of the fame denominations, wine-meafure, 231. The French meafures of Quantity ufed by chemifts, . The guarte is equal ta two pintes The pinte. spt two chopines The chopine ——— two demi-fetiers The demi-fetier == ~~ tWO poigons - The poigon prs four Paris ounces. of water at the freezing point. The proportion of the Paris ounce to the Eng» lith Troy ounce is, as63 to 64. As to the ri sfures of length, it is fufficient to obferve here, that the Paris foot is equal to 1 2,783 Englifh inches, or to the En ih’ foot, as 11410 107: Te ~ ' K3 : SAT and k 3 . BY MERCU RY - n this fubftance, and always acquire touch bodie quire: a convex or fj pL pa a va r. Fore HB Which : h €y have Beto hen they h anle long continued experiments upo ht Taian Ly r ; : un who gh y being kept A th ed with a patience unequalled even by the fearchers for the cians are oy none of it. Nea raer 3 and therefore that art of making gold, kept mercury in digeftion during 15 opinion, - that water rs efs, many good phyfi years, without obferving any change, unlefs that upon its iter which has been boiled . {urface a little black powder had formed, which b tritura- We tion was eafily reducible into fluid mercury. See PrRECIPI- Yillalvid by the Tey Sufpes, that fome TE Jrifgstss TE PER SE 0 ry alt eh ar : TA . ho rte Fe i, fenfible enn ii quantity is oo. are ) Till lately it was believed that the fluidity of mercury was €IVe to be repeated with due att ce. Thefe experiment as effential to itin its natural ftate as its volatility : fo that sation, fois ) thofe even who had labored to render it fixed and folid, ex- pected. to attain their purpofe only by producing a great we are affured, that Mercury, w : ry, when expofed to fir Ss prefents many remarkable i g iin Ta fi change upon its na ure, But at preient. = ¢ cold it may be rendered folid and: which had been phenomena. It fi is or eems to fi it ie Huperionts that of boiling Iochmse from a heat that d : y diflipated in vapors, like uk a greater heat by 3 fufhicient degree 0 Thi volatile bodies. malleable lke the other mE, Lg i hh lately demon conje - : demy at Peterfbourgh.. It under goes no alteration b ; y having been thus reduced into {trated by the Members of the Aca , ers availed themfelves of the intenfe cold on vapors for if the ey wife ercury be dified, it ade in clofe veflels, that : the / dy IS va ’ : . Fenians unchangeable by 35 before ops Spend : eis hie hop which they further encreafed by the artifi=" (tilled 18 ounces of i) epeated diftillations. B Sreury | cial fin 3 or i articularly b a mints of a fpirit of nitre with fnow, gill Mr. i Life's thermometer was funk to the 213th degree. They then perceived that continued to mark any other ch ange than t . oO . pe + . g the mercury in the thermometer no longer t it had loftits fluidity. were a li ave ittle encreafed, an | y the degrees of cold, and fufpected tha they found that their ken their thermometer, actually confolidated, They repeated this eters, and foun y- a purification of t] alteration of i of the mercury, rath oth Shi it. : The va ’ ther than bv a cher volatile bie, if hey cannon cape o che of 3] mescury was aually Sciences fi Po ons. Mr. » or be conden; | experiment upon other thermom . Kind 2 fay that he was ad the Acadeims of ceeded fo completely, that after having broken one of thefe fome.of it in ion preieading to fix ore i gt of this : ts, they extratted the mercury in 2 folid {tate, cury was. heated iron-box clofely welded ury had enclofed | fmall globe of filver, with a flexible filver i iibie vapors. it burft ‘the iron box, and di i | times witha A vt it sal lols 4 - adk 2 rd a : 3 : "i at : ; : ‘ A } = mio oh Elion ina ftrong heat, : , 3 tened and excended like a du&ile metal, Mr. Poiffonnier,: Ss mercury undergoes a m > Soptinued during feveral Phyfician of the Faculty of Paris, Phyfician to the King, oi i he Academy 1 Foie meal ot : 2 ’ a nt experiment, and was the perfon who’ {furface bein 8 gracually Chanved ; ged into a reddifh earthy powd al rators at this importa articular account of it to the Academy of Scien- without an, rh y metallic’ : ic luftre, which floats upon the fiurfac ¢ ace o firft fenta p (i). By this capital experiment it is hed well eftablifhed the fluid me : , I Cury with . quantity of me 4 out incorporati Shs powder. For ry may be gl i Thay any : art acquired,’ As Durpofe only the Proper Sn bata a red ces at Paris allie “precipitate . rcury, thus chan d € an veflels necellarv: thier. and as, fi Changed, refembles - 72, ory 5 this preparation Sh purpofe, no addition 1a 5 (i) The validity of this experiment, which feems to afcertain ai ercury precipitated by j ed mercurius precip; ois a the fixation of mercury by cold, has been quefiioned by Counfellor Lhe ftrongeft h ed by itfelf, ipitatus per : loved b eat which mere . Lehman: According to this author, the mercury cmpioye y ercury can {uftain is rn ols ofeffor Braun in the recited experiment had been diftilled in the ain 1s necefl: P cay Sommon method through water, and- che water oply in that ex» ; K 4 periment . 1p € é Je. ForB ; — - 5 er m—— he ~ — a a OY — : a i Se—— MA ——— - = ' MERCU RY eftablithed and aut fhec henticated, that mercury js, like other metals, fluid or folid, accord ing to the greater or lef: quan- of fire with which j¢ ; S penetrated ; that if we on] ecaufe it isfo fufible that fo mall for that purpofe.. ; This exceeding fufibility of mercury, and its great vola- with its great denfity and gravity Ppear contrary and incompatible to > and fo eminently, In fac, the denfity, gravity, and folidity of metals, leave no doubt but that the €rs in a great quanti ty into thejr compo- e calcination of jm \ » folidity and fixity fee perties of the earthy principle. How then that a fubftance compofed almoft entire] and refraQory prin of the moft fixed ciple, thould be exceed perhaps the ‘moft ingly volatile, and fufible of all bodies ? "This moft un. from the prefence of fome other principle y volatile and fufible, Buy what is this periment was frozen, but not the mercury. - He alfo affirms, thae having difti]led mercury without wat rified it from al] w er, and having carefully pu- atery particles, he cou mercury by artificial ¢ geal common merc Id not congeal the old, altho’ h i xability of mercury by cold, as a Peterfbourgh, unlefs we difbelieve what they affert concerning the ductility of the mercury thus hardened, which could certainly not be given by the congelation of adhering water, Nevertheless, mercury is faid to attra powerfully moiftyre from the air, The explofions occafioned by expofing mercury fuddendy to heat in clofe vellels, are faid by Mr, Rouelle to be pro- duced by water adhering to the mercury, ‘The water commonly obtained in diftilling mercury which has been expofed to moiit air, has induced a beljef of the convertibility of mercury ing water. Neuman fays, that | at the weight of Mercury was greater in winter than in fummer., Probably this difference proceeded from the mercury having acquired more moifture from the air in t he former than in the latter feafon, Excycror. tom. X. p. 373. doubtedly proceeds which is eminent] principle ? - MERCURY Se . ich Becker . rinciple whic! 2 Ts it phlogifton ? or that WH hich he calls mer- principle aod but not alentelngd, a ine Drinciple as mentiones, union O : are objects curial earth? ® 2 Je earth? Thefe certainly talents for and of this Hr iefity of thofe Sho have i € try. i worthy ! ft refearches in chem LA of mercury, whic 1 the fublime d now to the other prop he principal chemical We NEAT combined with the p | id rs org . it difcove ot a&, or but very ents. Sheu riginal ftate does n cannot be BV itriolic acid in its orig fubftances Vitriolic acic rcury. Thefe two ki hly concentrated, weakly, upon I lets the acid be very fo clidons are unite wii heat applied. i. oured upon mercury and a very lati Vitriolic acid, rated ; and as ei 1's ation. re concentrated ; united n difti es more and mo ted, it then als and diftilled, Becomes when it is gongeptEate 2 x 2 faline, itacquires a Sy diffolves it, and re d ercury, . : upon the m ortion of acl white mafs. tion we obferve, ut the De olatile ful Ton in diftillation is very muc s to fufpect that the which paffes in which might induce us le of the mercury. phureous Br the inflammable pe the vitriolic acid acid feizes par hen we afterwards fepa tallic fubftance has Neverthelefs, w we find that this hureous quality, from the BY This volatile fu > to the vitriolic received no ag probably to be Eh the mercury had heir afm hla matter ici matters generally acid by ome ld ft other metall Nation. : as mo . aminatl ‘ 9's fuper Shunde lk a more paricylas ese which remains Ih have. 1 . rial combination Whit to two dif- e-mercu . ides into When the le with pure water, bifid foluble in water, the retort 1sm one of which ‘is perie ¢ y white powder, if ferent ar recipitates’ in form o owder if the water and the othe N ; and of a yellow Phe portion which the wate Bo © fufficient quantity. mbination of Prost be hot, an . ater 1s a CO Ru it a ine oN in the water o give 1 remains diffolved jolic acid as 1s necellary : cryftallizable by with as much ye with a metallic ba Be Called witriol o qui, er I. Ee almoft entirely use evaporati . itated portio 3 0 ive it a alin mercury. The g on. tao little acid x lly deprived mercury, y r bility in water. It Tey a fufficient lavation quality, or io a to Mr. Beaume, by s more and more of its acid, accor This precipitate Petomes Citls a violent with har it is wafhed with hot water; emetic, ‘ 3 wien yellow, corallinum, See emetic, and fd.& that article, ~~ fy inftead 2) 0 wl J03, am triol of treating With water the combinas: diftillation, ibe’ cobiol, which: remains in nation of vi- “emery fays, that he ated fevera] times with € retort after pregnated with acid, anc 2% vitriolic acid, 1quor, which fo mercury, . If the ¥ i : combinat; pofed to fire, kon of. ¢ th and this Pons part of this thus with vitr: le thin ha vitriolic aei ai ppens, t quently feems lis fend fuftains a Saat mercury treated. pure. e fom cat, and confe- ewhat mor e fixed ! Nitrous acid than when it is diffol ution prefent ves mercury ve : tion of filver by! NON very miler oily : and this fo- pure; the fo] rds fame acj is 33 Hof of the folu- ive, and blacker, may be’ made Withee Yought to be ve olution of filyer To the fkin, in the fame €at ; it is corro- by cr fallizatt,, es. - From this folutio manner as the Called mercurip) py 2 Mitrous mercurial alt may be obtained ire. If this falt be expoied ¥ ich may be Tre 0 the a&tio be driven from it SRE acid quits the, becomes’ ercury. everthe.-. 3 0 cid, and at ine y more and m me “chemifts have j es a ve ore im- ry corrofive mproperly called of of € expelled :, Powder which Pe 1ublym cid has the ann. TANS after the ev It js called appearance of ‘mercury aperation of pitate, See P precipitate, but impor FP rated poured pon "RECIPITATE. When per y for it a / ra ; it o wine : -i : RE ‘ ' 18 Cc . : arine acid when SiEtrate (Rep), alled aregnym hes. 10 its ordi quid does not 3 fenf; heat. €a tly unite toget marine fa]¢ ne, and eve eets mercury alfo in vapors, t n intimately, Heo = intial J. Hence refults a tened needles esate of whi Ed It is called corroffy ich ran te fublimate, beca fe iti th oo » and is at the {ame ti a gs me a very vidlent fis of Corrofive : MERCURY ] - “ Dorrofive fublimate may be made in feveral methods. The imoft common is to take a {olution of mercury evaporated to ynefs, tO mix it with aquantity of calcine martial vitriol and of decrepitated common falt equal to the quantity of mercury diffolved, and to proceed to fublimation by expofing the mixture to fire in a matrafs fet in a fand-bath. On one fide the acid of vitriol diféngages the acid of common falt which Sts in vapors. On the other fide, the mercury is reduced into vapots’by the heat. T hefe two bodies combine together in that ftate, and form a falt, which being itfelf vola- tile, attaches itfelf in the upper and colder part of the matrafs, where it forms a very white and thining cryftallized incruftation, which is the corrofive fublimate. The other methods of making this falt are founded on the fame prin- ciples. ‘They wil be found under the article CORROSIVE SUBLIMATE. » This falt is of a fingular nature, and differs much from all the other combinations of mercury with other acids. Altho’ it is extremely cauftic, and is capable of receiving fill a confiderable quantity of mercury, as we {hall after- wards obferve when we fpeak of fweet mercury, (which qualities indicate an imperfe&t faturation of the acid) it neverthelefs has none of the properties obfervable in thofe falts whofe acids are imperfectly faturated. It cryftallizes well, and very eafily; fo far is it from being deliquelcent, as all thefe falts are, it is difficultly foluble in water, and requires a large quantit of boiling water to diffolve it en- tirely. It is confequently 2 {alt which cryftallizes by cold. Its cryftals are of the (ame form as thofe obtained by fubli- mation, and crofs each other irregularly. They refemble a heap of large fword-blades or poignards thrown carelefly together. If corrofive fublimate be expofed to fire, it will again be {ublimed in its original form, without being decompofed, or at leaft only infenfibly The mercury then, fo far from receiving any fixity from the marine acid, as it does from the vitriolic and ‘nitrous acids, feems on the contrary to be rendered more volatile. This phenomenon is analogous to thofe which are exhibited by cther metallic fubftances with marine acid, the union of which renders all thefe fubftances more or lefs volatile. ‘This acid ought to produce this effect more ftrongly upon mercury, as it is itfelf confiderably volatile, This property, as well as the others which are peculiar to the combination of marine acid with mercury, are naturally . -deducible deducible from. n ERC URY b : ref i this oH yin both thefe fbi. OF Mercurial MERCURY ect ele fubftances, ; earth exif i: ROSIVE). was luficiently proved Hf Becker's pi Ring tions by acids. Thefe termediate fubftances are abforbent : ie n The affip; . O¢¢ SUBLIMAT earths, and alkaline falts, both fixed and volatile. it overcharges oF ar ine acid with m TE (Coz, Lime-water mixed with 2 folution of corrofive fublimate, quantity of that elf in fome al ercury is fo great, ¢h fecipitatesthe mercury in form of a red brick-colared powder. triturated in 3 o] a etallic matter, IF ith a confide Lat Rbis mixture is employed in furgery under the name of the mercury so = OMar with fluj Corrofive Fahle bagedenic waters It is ufed for cleanfing ulcers; particularly mercury till C thofe which are venereal. : combination ri inonif By thus addin. Fixed alkalis precipitate mercury from its folutions in a tints = reddifth powder; volatile alkali precipitates corrofive fubli- mate in a white powder, and the folution of mercury in nitrous acid in a grey flate-colored powder." 1n general, the colors of the mercurial precipitates are various, and thefe colors depend, like thofe of all other metallic preci- pitates, on the degree of divifion of parts, and on the quan- tity of faline matter and of -phlogifton retained by thefe fo fu blima tion c fublimat : d.:} +1aLC Is com hich the opLsstedy precipitates. Sec PRECIPITATE. ; ar ve fublimate, lien | Fixed and volatile alkalis do riot a&, or but infenfibly; ort oa render the comb; mercury, in its proper ftate ; but they can diffolve it, as ‘mate is then ca] d well as al] other metallic matters, when they can be applied to quently foyer Tr, thefe metallic matters very much divided, as, for example, i I> previoufly diffolved by acids. Thus when a folutien of mer- ! wil See M cury, with more acid than is neceffary to diffolve the mer- hame is f1i]] in oF “a alba, the white FRCURY (Sweet), | cury, is poured into avery concentrated alkaline liquor, the Corrofive fublimate ; cagle, and this Latin ’ recipitate formed upon frft mixing the liquors will be again addition of meres C18, 00t on] a. diffolved, and will dif The volatile alkali mayb ir mercury, whi ! ] iffolved, and will C1 appear. e volatile alkali may by hoi the properties ch ch it Fore, : this management diffolve a very confiderable quantity of ities, are alm € ma : mercur not then, prope v faline ery fp caking, b on ordinary mercury, are alfo capable of diffolving it when which is the moft 4 moft : | it is fufficiently divided. Thus if we pour a large quantity g : of diftilled vinegar upon mercury preci pitated by a fixed alkali {ublimed, ;¢ lof; pe from its folution in nitrous acid, this precipitate will be ’ e » and at laff o]) Sige hore and : eafily diffolved again by help of a little heat, and from this > the com- oft entirely ah, : d 3 Lattly, vegetable acids which fcarcely have any action up- combination a mercurial falt of a fingular nature will be formed. ) or. nerd] The acid of vinegar, and probably all other vegetable clent ao A Panacea, J i acids, feem tobe capable of contracting a very intimate union (S £ P gcse taken in. with mercury ; for the acetous mercurial falt which we have . Oduce falivation, +t mentioned is not only cryftallizable, but is even diffi- cultly foluble in water. Hence, the phlegm of the vinegar, . not being in fufficient quantity to keep the acetous mercurial {alt difiolved without heat, when it is made by the procefs defcribed, this falt cryftallizes in great quantity, when the liquor cools. Its cryftals are mall, fhining, thin plates, tions | floating in the liquor like pieces of filver leaf. | From fay, turb; : s turbith mi Lr Inera] WC VIE } py "Ee Vitriolic acid js joined to the Cnt happe that js gq the mercury, | Bpen.but becaufe 1t feparateg cs . contain this ach common fat, ang in of mercury ; id, mixed jp, ¢ TY IN nitroyg ac: from pe marine a Occafion a precip; om € Nitrous acid pon the mercur Pitate by the acs mbination, which : and with which % which jt feparates, 1 : y } a unites, for ears ag : i PP IS as a white ming a, general a] falts whie] Manner with 4 or a fimilar Lidiz ai They MERCURY “The reafon why this mercurial falt is much lefs foluble-in ‘water than the “hitrous mercurial falt is, that the marine : acid is more intimately joined than the nitrous acid with the ‘mercury ; and alfo becaufe marine acid has fo ftrong an “affinity with mercury, that it overcharges itfelf with that “metallic matter, whenever it meets with a fufficient quantity ‘of it, as in the prefent experiment. For if we add to the white precipitate, to corrofive {fublimate, or to any other’ combination of marine acid with mercury, a much greater quantity of ‘this acid difengaged, thefe faline mercurial mat- ‘ters will charge themfelves with it fuperabundantly, and wilt become fo much more foluble in water, as they.fhall have received a larger quantity of this acid, according to the general rule. See SALTs. : Fence if white precipitate be made by pouring a confider~ able quantity of difengaged marine acid into a {olution of mercury by fpirit of nitre, the precipitate ought to be re~ diffolved : and it accordingly is fo, as Geofiroy, Junker, and Pott have obferved. As in this experiment, Mercury is found diffolved in a liquor containing the nitrous and ma- rine acids, fome chemifts have imagined that mercury was foluble in aqua regia. Neverthelels nothing appears, lefs certain than that conclufion. For it is very poffible that mercury may be kept diffolved by a_fuperabundant quantity of marine acid, ‘with which only it is really united, and that the nitrous acid fhould contribute nothing to this folu- tion. Befides, if the nitrous and marine acids could be both tihited to the fame mercurial parts, why do the white pre- cipitate and corrofive {fublimate, both made by help of a- large quantity of nitrous acid, contain only the marine acid ? The {malleft veftige of nitrous acid cannot be difcovered in them. * .. .._ Mr. Pott, in his Differtation on Common Salt, mentions another fa, which feems to prove not only that mercury is foluble in aqua ‘regia, but alfo that nitrous acid may feize upon that metallic matter exclufively of the marine acid. Mr. Pott’s expériment confifts in pouring fpirit of nitre upon corrofive fublimate, by which he obferved that fpiyit of falt was difengaged in vapors. : A modern author draws from this experiment a tonfe- quence againft the greater ainity of the marine acid than of the nitrous with mercury, fuppofed by all chemifts, and even again the do&trine concerning the tendencies of bodies to one another according to certain laws, called Affinities. But, 1 believe, we may affirm that this experiment is only capable of IS againft even the mo good philofop : y others we attentively I oe heat, jt is orrofive fyb]. nd as the mix. fcare ely poffible MERCURY cury. But as the marine acid and mercury may be united in very different proportions, according to the ftate in which they are prefented to each other, in this refpect very confi- derable differences ought fa be found in white precipitates, according to the methods/of preparation. If, for example, mercury be precipitated by a large quantity of difengaged marine acid, this mercurial precipitate will moft HL contain a much larger quantity of acid, than a precipitate made by adding common {lt to the folution of mercury. If this be true, we need not be furprized that chemifts thould difagree in their opinions concerning the degree of corrofive rs to be attributed to this fublimate from white precipi= tate. We have feen above, that the combinations of mercury with acids may be decompofed, as all metallic folutions may, by earths and by alkalis both fixed and volatile. They may be decompofed alfo, and particularly corraofive fublimate may, by feveral metallic fubftances, fuch as tin, regulus of anti- mony, and copper. Corrofive fublimate, being mixed with tin and fubjeéted to diftillation, may be decompofed. The marine acid is applied to the tin, a part of which it carries with it in diftilla- tion, and with which it pafles in form of an acid, fmoking liquor. This acid is called the Lioyea (SMOKING), or SMOKING SPIRIT of LiIBAVIUS 5 which fee. Antimony, or its regulus, being mixed and diftilled with corrofive fublimate, alfo decompofe it ; the regulus taking the marine acid from the mercury, and paffing with that acid ip form of a thick liquor, which congeals by cold, and is known by the name of BUTTER of ANTIMONY. Sec thqt article. : If very clean plates of copper be fteeped in a folution of corrofive fublimate, the acid of that falt will attack the cop- per, and the mercury will be depofited upon the furface of the copper, with its metallic luftre, which always happens when one metal is precipitated by another, See PRECIPITA- TION and PRECIPITATE. As mercury revived is always fluid, and therefore capable of being allayed with any metallic matter which it can touch, it amalgamates in the prefent experiment with the furface of the copper, and forms there a beautiful], white, and fhining filvering, capable of furprizing perfonsignerant * of thefe effets, and of making them believe that copper is thus changed into filver. But to make this experiment fuc- ceed well, we muft add fome marine acid, or fome fal ame Vor. II, be moniag MERCURY moniac to the folution of ‘corrofive fublimate, ment facceeds equally well with the folutjon of mercury in {pirit of ‘nitre, but always better when the acid is larger in quantity than is fufficient to diffolve the mercury. The fur- : omes inftantly "This experi- face of the copper immerfed in thefe liquors bec filvered, and then it muft be immediately Withdrawn, wafhed in’ clean water, and wiped by rubbing it with a dry cloth. When corrofive fublimate and the other ‘combinations of mercury with acids are decompofed by proper intermediate fubftances, the mercury is always by that operation revived, that is, ‘reduced to a fluid ftate, and is obtained in that ftate by giving a heat diate fubftance is when the operation is made by diftillation, fufficient to raife it. But when the interme a compound body, fuch as antimony, which contains a prin- ciple capable of uniting and fubliming with mercury ; then the mercury which is difengaged from the corrofive fublimate, inftead of being revived, makes part of a new combi nation, and is fublimed in form of cinnabar, if antimony was ufed, ntimony. from the union it contra&s with the fulphur of the a “See BUTTER » ANTIMONY, and CINNABAR. Sulphur aéts ftrongly on mercury. If thefe two f{ub- ftances be triturated together, divided ; ‘its molecules will be the fulphur, and will adhere to j 2 color more and more brown, or blackifh, which is a certain fign of the divifion of the mercury ; inaword, the mercury difappears entirely; becaufe it is extinguithed and incorpo- rated with the fulphur. “When the fulphur has thus abforbed all ‘the mercury which it can receive in this method, the mixture is cated ezhigps mineral, from its black color. The fame combination may be made by fufion, that is, the mercury will be eafily diftributed Betwixt thefe of t; the mixture will acquire by mixing the proper quantity of mercury with’ melted ful- phur. Thefe two fubftances unite together, as when tritu- rated, and form a black com pound, called ethiops made by fire. By this method the union’of the fulphur and of the mercur is made much more quickly, and fomewhat more intimately. See ETHIPOS MINERAL. When mercury and fulphur have been united together only by fufidn’ or trituration, the union is not fufficiently ftrong, ndr the proportions fuitable for‘making the moft perfe&t and moft intimate combination, called cinnabar ; for the prepa- ration of which fublimation is neceffary. By fublimarion “of "the ethiops, the mercury and fulphur are rzifed together, and are more intimately combined. But we muft obferve, that in this fublimation a part of “the fulphut of the ethiopsy 24 which MERCURY ¢ gi : ; which is fuperabundant to the combination of cinnabar, is ins united d; fo that only one part of fulphur remains uni re ts parts -of mercury. This fuper- “abundant fulphut is not entirely feparated by one fublimation. imation muft then be repeated feveral times, that The lob may be entirely free from the fupsrabundant fulphur. The fublimate, which is at firft black like gt iops, becomes more aiid more red, as the mercury and fulp or ap proximate more and more to their proper proportions; an laftly, it’ remains in form of a very weighty, Sep-t , ftriated mafs, when the cinnabar is perfect. The re ie g of the cinnabar is fo deep, becaufe the matter is excee ng y denfe ; for when it is finely powdered, it acquires Ry red’ color; and is then called wermillion, which is ufed in Pe his combination of mercury with fulphur is found na- tive, and is called native cinnabar, to diftinguifh it fom that made by art. Native Spahr is mercury mineralifed, or mercury. e¢ URES. { ; he Fomsrny of mercury and fulphur is fo ftrong i cinnabar, that the principles of this compound are not a = united merely by the ation of the fire, without basing i e fulphur. ‘Thus cinnabar expofed to fire in clofe ve els, does only fublime, without any decompofition or alteration. To decompofe, therefore, cinnabar, and to feparate the er. cury from it, fome intermediate {ubftance muft be emp oF ] which has greater affinity than mercury with fulphur. T ¢ e intermediate fubftances are calcareous earths, fixed alka i iron, copper, lead, filver, and regulus of antimony. y then, cinnabar be mixed with any of thefe fubftances, an be diftilled, the mercury will difengage itfelf and pafs into the receiver, where it will appear in its proper fluid form 3 and the {ulphur will remain in the retort combined with the i iate fubftance. Fag nee obtained in thefe operations is faid fo be revived from cinnabar. It is Jully confidered as the pureft, and fitteft' for chemical and medicinal purpofes, and even for the arts in fome cafes where very pure mercury is required. The mercury obtained by the decompofition of cinnabar is not only very pure, but the whole quantity which was in the cinnabar is thus obtained, when none of it is loft in the operation; which proves that mercury fuffers no alteration : e fulphur, See CINNABAR. ; i from what we have faid at the begin . . - - J ; . 5 tal . ning of this article, is to be confidered as a melted metal, L 2 alfo with earthy fubftan It may be very well all. in the following hrm Zinc, regulus of antimony, € metals capa ith method hae pable of unitin together, The allays of mer cu it and are employed For ity w ith metals are called amalgams ? 8ams of gold and filyer he Loven Purpofes. The ama]. ing, and for the extraq:.. Pioyed for ores; that of ation o tane ; that of tin curial balls, and f, alls, or the preparat; 1bavius, See 4/7 thefe words, hall id A ad, tin, co pper ) umbered am ; g with mer a yet been difeovered by which a WA e Aron 1s not n AMALg AM. LLAY and trituration. much divided : : Shadi iit difappears, is perfeltly ext; iil Gy and leaden color. i - nd} at 18 called mercurial ointm 2 ae 3 as we thal] afterwards dered mere] il 4 if eg a im the fat : ort : und on the contrary, Aubftances ; for on tes nguifhed, and ac- his combination of mer- ent, iy and is very ufefu] cannot be fep been verified by Mr. Beaumé, . ¢reury, expofed to th inte boil; : > the vapor of mel folid, Sling linfeed oil, lofes its Auidity, Jead, wl thrown though, pr y be formed into toys tad final] comes fo Hon of 1 p Spey fpeaking, this is onl mall utenfils, little hats on a fluidity rah to . . ey er. principle in thefe Ee proves, neverthelefs, th : 2 capable of acting fenfibly wim their phlogifton, js Perfons MERCURY Perfons engaged in the difcovery of the art of making gold, or of meliorating metals, confidering that mercury has the metallic luftre, and a gravity approaching to that of gold, have endeavoured much to fix it; thatis, to deprive it of its volatility and fluidity, intending always to give it the color of gold afterwards by a philofophical tincbure. The falfe fixations of mercury above-mentioned feem to indicate, that if any method by which mercury could be fixed were dif- covered, which is not very probable, this method muft confift in giving it fome principle that it wants. Neverthelefs, all the properties of mercury feem to thew, on the other fide, that “its fufibility and volatility depend on fome metallic principle united with it fupesabundandy ; and, confequently, that its fixation ought rather to be effected by depriving it of fome principle, than by any addition. However, we are certain that it muft be effected by the one or the other, or by both the caufes united, (#) Mercury i (#) The purification of mercury from extraneous fubftances is important for the purpofes of medicine and of the arts, and efpe- ¢ially for fome nice chemical operations. Mercury may be cleani- ed from duft, by ftraining it through fhamoy leather; from reafe, by wathing it with an alkaline lixivium ; from any al- Raline matter, by vinegar; from lead, or bifmuth, with which it is frequently adulterated, by diftillation ; from fulphur, by mixing it with quicklime or with filings of iron, and then dif- tilling the mixture, The beft method of purifying mercury is by reducing it into ethiops mineral, with which twice the quantity of quicklime or of filings of iron is to be mixed ; and by diftilling it from this mixture. Its purity may be known, by obferving that it does not foil clean white paper ; that it has no pellicle on its furface 3 that when triturated with water, it does not foil the water ; that when expofed to fire, in an iron fpoon or ladle, it does not crackle; and, laitly, that it is perfectly and entirely foluble in pure fpirit of nitre, without any depofition. Mercury may be united with all metallic fubfances, excepting irom, arfenic, and the femi-metal called nickel. See a note under the article Iron. Dr. Lewis obferves, that in fome cafes mercury ab- forbs gold and filver from their folutions in acid and in alkaline liquors. This it may do by precipitating thefe metals, from its greater affinity to thofe menftruums, and by uniting or amalga- mating with the very minute particles thus precipitated. The mercury of an amalgam expofed to heat, raifes along with it fome of the amalgamated metal, even of gold, as happens in the gilding of metals by amalgamation, Mere diftillation, there- fore, may not be fufficient to procure mercury perfetly pure from L 3 metals, ~ Mercury ; CURVY ow Wit) IS one of the metals vw y £0 the art which bef deferves to pe wel] : 0 » given Hop oh wo eafes to which artis wh wh ever that may be, - hot Oventured to ufe re A it fuccefsfully , vim oy fkin, Y againtt the “When the Mor venereal dif; army of Charles yyy © Leafe firft 2 : called Besa ol a¢ the By in Europe, in the arpu, confiderirg oles; a phyfician € new difeafe of 2ereyyy m fh ’ > € fhall mengjq tate 0. 1. Mercy ral methods ; r. Brandt re] e ho oloain du ring he ued oy hear, . ate 3 » n - . re ’ 2Ppears capable of vg aio experi I Vidfable iy 0 detained » 10m Which merce, ble part of and fixed by digeft: ercury J ft . enfe heat, ot be feparatag vid Ky it Cann at that cap p . | of the m € applied ¢ limate be Whining dp dg : the fub); d Y {ublim ays, that if med m . ed with {; ; mercy at laft fo § atter mixed jy}, the 2 ammonia, and ry fub. xed in th d each tj he fire, tha; dum, the whole Boor it can Bot be any more fublimeq, difcovered MERCURY difcovered itfelf by cutaneous puftules, fimilar to thofe of malignant itches, and encouraged by the example of the Arabians, attempted the cure by mercury, and fucceeded. Nearly about this time, chemifts and alchemifts directed much of their labors towards medicine, and difcovered many chemical remedies, the beft of which are preferved, and em- loyed at this time with fuccefs. The famous Paracelfus chiefly diftinguifhed himfelf in this way, and treated vene- real difeafes with aftonithing fuccefs, by internal remedies, in form of pills. Although he has not publifhed his re- medies, it is believed, from their effect, that the bafis of them was turbith mineral. Since that time mercury has been ufed in a great variety of forms. Crude and fluid mercury taken internally produces no effect in the body ; becaufe the adhefion of its integrant parts to each other hinders their divifion and diftribution, or folution, without which it cannot have any effect. In its “crude ftate, therefore, it does nothing but load the ftomach and inteftines, It falls downwards by its weight, and goes out of the body along with the feces in the fame {tate in which it entered, tT Several phyficians have believed that mercury, fwallowed in its crude ftate, may be ufeful in the iliac paffion, imagin- ing, that by its weight itis capable of reducing the inteftines to their proper fituation. But the effects are not {uitable to their expectations. ‘We have even feen this difeafe rendered worfe by mercury, from the thooting painsit occafioned in thefe parts, already pained and irritated by fpafms. The ufe of crude mercury is now abolifhed in thefe difeafes. But when mercury is much divided, {fo that its molecules cannot again unite and form fluid mercury, in whatever manner this divifion may have been made, it then produces very ftriking effects, and fuch as may be expected from the moft powerful remedies. ’ Mercury adminiftered in this ftate accelerates the pulfe, divides and carries off the thickened humours, augments in general all excretions and fecretions, but fome preferably to others, according to circumftances. If it be ina faline ftate, or capable of being eafily put into one, and be thus intro- duced into the body by the ftomach in fufficient quantity, it alts as an evacuant, purgative, or emetic. Mercurial frice tions and fumigations chiefly encreafe the fecretion of faliva, and this in proportion to the quantity and number of dofes. Mercury, in every form, if fufficiently divided, cures dif- La cafes ; f he folution of §, de We thal] oe \ _ Mercury prec ny ations of mercury, ment; Pable of entering. aed Per fo; being much dio: dofes from two : : € blood-veffe]s® Hoda divided, ite dn 1X 3 When] 4 ° eit Properly repe given in ine j otwi peated ew, that j¢ ma everthelefs, chig Caufe it is very Cparation dear, The ¢ fe ws a .._ 5 1€ combina; Vitriolic acid tio »P erhaps be wh .. : ie a fufficient quantj¢ Water; js Very corro of 1 vey €reury in the tre, are j uftly rankeg among nitrous acid, and ft corrofiyes, mercy Some MERCURY Some perfons, and Lemety amongft others, fay, that they gnay be taken internally if they are diluted ; an ounce of fo- lution, for example, with 24 dunces of water or ptifan. This is called mercurial water. Lemery fays, that from half an ounce to an ounce of this mercurial water may be taken in a glafs of ptifan, or broth, and that it vomits gently, and excites falivation. Mr. Baron, in his notes on Lemery, juftly exclaims againft the ufe of that dangerous remedy. Neverthelefs phyficians of great reputation have introduced, and even fuccefsfully, the ufe of corrofive fublimate for the cure of venereal difeales, although this preparation is no lefs corrofive than the folution of mercury in nitrous acid. A pomatum is made of two ounces of mercury diflolved in a fufficient quantity of nitrous acid, and mixed perfetly well in a mortar with two pounds of hog’s-lard. This pomatim admirably cures the itch. The {olution of mer- cury aéts powerfully upon the hog’s-lard with which it com- bines, and to which it gives greater folidity, while at the fame time it is itfelf rendered thereby much milder. The pomatum is of a citron color, and is to be lightly rubbed ‘upon the parts attacked by the itch, which by this treatment foon difappears. This pomatum for the itch comes from the Hotel Dieu at Paris, where it is given to convalefcents, by which they are quickly cured of the itch, which theyall catch by remaining fome time in the hofpital. The receipt of this pomatum is alfo found in the laft edition of the Difpenfatory as Paris. Red precipitate is not ufed internally, butis employed ex tefnally asa detergent and cicatrifing efcharotic in the treat= ment of venereal ulcers. All the combinations of mercury with marine acid are ufed. Of thefe the corrofive fublimate has been the leaft ufed, in France at leaft, The terrible accidents and deaths occafioned by fmall dofes of this preparation have confined its ufe to externalapplication, as an efcharotic; and even then it is generally rendered milder, or rather decompofed by mixture with quicklime. But fome years ago Van Swieten, a difciple of Boerhaave, and principal phyfician to the Emprefs-Queen, introduced the internal ufe of cor- rofive fublimate for the venereal difeafe. This great phy- fician diffolved twelve grains of fublimate in two pounds of malt {pirits, and gave this folution by fpoonfuls, diluted co- pioufly with emoltient liquors. A great Parations of mercury, ufe of Corrofive fybj; ongft the 8 With al] fore the Tartar and am Manner of Jjyin continua] accu * this remedy, excellent the ufe of it. €y obferve, th, to agree with ¢ of Corrofive fy concerning the m, in € employed 25 triolic and 'pjq, ous more, perha ury with whi are not ve fublimate . an being more difpofeq ’ they are Y be ufed ut notwithftang. ch iy w the marine acid it fl] retains f¢ enfibly a falipe quality, MERCURY four grains to ; ive, when taken from ifeafes quality, and thy treatment of Jeers 5 fo riot igor 18. It PE it is intended to DS remedy only. passe a the cure he 2 rT as faline, als, ufual to a : whichis on ived of its f { panacea, rcury deprived of i The mercuria : ] fimply as mers : ality in when taken es to Sasa) feline all fuidity/but tg canal : accordingly it in a large enough the Bliienteny 0 falivate, when given . to twenty-four quantity. The to be repeated as occafion fetfion cure the “or thir ¥y. gs Several perfons of the profe y proper Intery : aly. . re faline pox 4 this OY ever it med and White preci : Accordingly it e ity : but it is ‘ tity ; but 1 “than {weet mercury cautioufly and in lefs quan five : : f ufing corro mutt be given pe lls. if the propriety o Ho be ad. hitglewiely, HE this p spas ny : It would fiblimere m Apa with proper WA dofe. vantageou y ce the fame effe&s in a arg Binattons ofipens Po fonhble eel is a No en hether ethiops or 0 reject ARE Eh aod tenon ed nally, an me arations as u ya i has no faline thefe mercurial prep united with fulphui be- v ; ercury ; ftruums, be gut, do very He ed pon bens quay, fended by the fulphur, caufe it is defen i tim : | . {ions and ifeafes, and fuccefsfully The bod. Re pt patient venereal ro by burning. 1 ar difengaged then it is f mercury, . hem- . he vapors :o ial ors infinuate t is expofed to t Thefe mercurial vapor falivation, and by this burning. of the fkin, excite {a > oe ves through the Ay This is called the method by fun cure the yenere . duced by gation. et very little the effets Siig 1 er be true Ve ow ye mercury with Fog ue mercurial combinati a for their bafis fe ’s pills have fo rthelefs fuppofe, that Keyfer’s pi ble ; we may neve -oduce good falt, as is ey hh fa this form might produce g that mercury &t oe- : the moft g i of all the prep frStions Prana ointment. aftly, : inly that c ian t= s certainly : fhed by tr nerally spiployed 3s 8 above, mercury BEE ointment It 1S, ‘as we men " ly method of u ing is turation with fat. The only u : 2 \ 15 is all thas Y mercury, The Manner of the an : n of the Gi Phyficiang believe, ¢ S s ~ “Ys and pare; mig when j¢ Is adminifior, 0 : j ave beep believed : intment 1sonly div: : Xt the parts of th, Livided, difperfed mb t L bined ; and this y (ithaut bein d opinion. s that mercury in > and inter. 8 truly dif MERCURY conclude, that mercury cannot cure the venereal difeafe bue when it is really diflolved, and deprived of its properties of fluid mercury ;° that only the portion of mercury in the oint- ment, which is thus combined, effets the cure, and that the other portion of the mercury which remains in its natural ftate in the ointment (for much of the mercury is in this ftate) pafles into the body without producing any effet; for which reafon the mercurial falts cure in much lefs dofes ‘than the mercurial ointment; that, laftly, if the portion of mercury introduced into the body in its proper ftate by frition or fumigation contributes to the cure, the reafon of it is, that the moft divided part of this mercury unites within the body with fome greafy or other fubftances with which it is capable of combining ¢ If this be true, ought we not to fearch for fome new combination of mercury, which fhall be at the fame time very foluble and free from caufticity ! Such a remedy would certainly be very precious. For although the mercury of the mercurial ointment is not cauftic, and although the me- thed by friction is undoubtedly the moft advantageous and certain, ‘it is not however free from inconveniences. It frequently expofes to dangerous falivations, accompained with very troublefome accidents ; and if to avoid them, the quantity of ointment be diminifhed, and the intervals of the feveral fri¢tions lengthened, by which indeed thefe accidents are avoided, the cure then is not only of a tedious length, but is alfo fometimes imperfect, or lefs certain. But have we reafon to flatter ourfelves with the hopes of finding fuch a preparation of mercury? If we confider that meres} has been tried in a great variety of methods, and by very able chemifts, and that, notwithftanding, no prepara- tion has yet been found free from inconveniences, we fhall be apt to defpair of fuccefs in this inquiry. But on the other fide, if we reflect on the nature and properties of mercury ; if we confider that this fingular fubftance, as we have feen in the prefent article, is perhaps one of thofe which may be combined in the greateft variety of manners ; that it is acted upon by almoft every folvent; we may ftill have hopes of finding a mercurial preparation, not only much fuperior to thofe hitherto known, but which perhaps {hall be attended ith no inconvenience. The ufe of mercury is not confined to the venereal difeafe. We have already feen, that its antivenereal quality was dif- covered from its property of curing the itch, even the moft malignant ; and, in faét, it does cure much more edlly an i Cutanegy e feversf t . ter k of mer : £ Cury, hb Or the Venerey] ar ame prepa- Ome Obfervation Pleyed as ve hopes, that by > Dut fortunate], $m mercy y hope, that fo Y In othey difeafes 0 Powe R Cc alfo aquila aj}, Is Operations with Te afterwards fub]; 0 mak turated Care I$ to be 34 fully ; -ury, Corrofiy ; . ded Ka a glafs mortar wah mare Salle ually as je difappears 5 me . 1181 to difeafes - MERCURY tinued till the corrofive fublimate is faturated and will re- ecive no more mercury, which is known by the globules not difappearing by trituration. Lemery fays, that corrofive fublimate can only receive about three quarters of its weight of frefh mercury ; neverthelefs a larger quantity, a half, may without inconvenience -be added, becaufe thereby the cor- rofive fublimate will be more perfectly edulcorated, and the fuperabundant mercury will be eafily difengaged ; as we fhall foon fee. The corrofive fublimate receives from the mercury with whichit is triturated a blackifh-grey color, which color mer- cury always acquires when it is muchdivided, and ftill retairis its metallic ftate. This grey matter is to be put into one or more matraffes with fthort necks, or rather into the veflels called medical phials, fo that two-thirds of the containing veflel fhall be empty for the fake of the fublimation. ‘Thefe matrafles are to be placed in a fand-bath, and funk in fand to the height of the contained ‘matter. The fire is then to be gradually augmented till ‘we fée that the fubli- mation begins. It is then to be kept in this ftate till it be all fublimed, and attached'to the top of the veflel, excepting a {mall portion of fixed matter which remains at the bottom. When the matraffes are cold, they are tobe carefully broken. "The white compact fublimate is to be feparated from fome lefs white and denfe adhering to the neck of the veflel, tobe again powdered, and fublimed a fecond and ‘a third time'in the fame’ manner, always taking care to feparate each time the compaét white mafs from that part which has lefs of thefe qualities. ‘The fweet mercury is then in its’ moft perfeét ftate, a white, heavy, femi-tranfparent mafs, fmooth as glafs in its convex part, where it adhered to the veflel. In thefe operations no mortars muft be employed, upon which the acid or the mercury of the corrofive fublimate can act: therefore neither marble nor metal mortars are proper, but thofe made of glafs. | Although the crude mercury which is triturated with the corrofive Rice is joined to it fuperabundantly, and con- tracts with it a certain degree of union, this union is not nearly fo intimate as it may be, and as it.is after the perfect dulcification of the corrofive fublimate ; for if we take inter- nally corrofive fublimate impregnated by trituration alone, with all the crude mercury which it can perfectly extinguiih, it would produce neverthelefs very violent corrofive effeéts. By fublimation then the new mercury is completely com- bined with the acid of corrofive fublimate, which is thus | rendered € mercyri,] a > nger, It . 1ts fa]; i ine € uro Pro- it lofes Its pure eight ine fino. $: and jf weet AN nd S, or ACEA. is then ca]ley fiihaps lefs, CURIA : tort n s par- IMperfe&y combina. e fublimage, and mug : “en th ay. for their fu bli wi io xpofed For atile bod i more. fenfib] the {ublj- of a] in the Operation MERCURIFICATION operation for {weet mercury, fometimes fragments of the matrafles in which the fublimation had been made, and which adhere to the matter which is again to be fublimed, are raifed along with the mercurial fublimate. Mr. Beaumé has fre- uently found large fragments of glafs in the middle of maffes of the fublimates, which had been made in great works, where the fame care and attention are not given as in the fmall operations of chemical laboratories. : Lemery remarks, that {weet mercury acquires a yellowifh color when it is triturated. This color proceeds from the quantity of mercury being confiderable with refpe& to the acid; for that is the ordinary color of mercury when it is much divided, and has not its metallic luftre, as we fee from the example of the precipitate per fe, of turbith mineral, and other preparations of mercury which are in this ftate, See MERCURY, and SUBLIMATE (CORROSIVE). - MERCURY of PHILOSOPHERS. Alchemifts have given the name of mercury to many other things be- fides the metallic fubftance generally fo called. This latter they call ordinary mercury, and valueitlittle. We cannot - precifely fay what they meant by their mercury, from the obfcurity of their writings, and alfo from their different de- fcriptions of the matter, No term is more frequently ufed by themthan this. In every page of their writings we find the words mercury, mercurification, &c. Probably they had not all the fame ideaannexed to the term philofophical mercury. The moft probable opinion upon this fubject is, that this mercury is the metallic principle which Beccher has called mercurial earth. See EARTH (MERCURIAL), and the fol- lowing article, MERCURIFICATION. Mercurification is an al- chemical operation, by which metals are faid to be reduced into a fluid, heavy, opake, and fhining liquor, like ordinary mercury; or by which the mercurial principle may be ex- tracted from metals, ¥ obtained in the form of quickfilver. But thefe mercurificd metals, or their mercurial principle rendered fenfible, are a kind of philofophical mercury, which, although they refemble ordinary mercury, are neverthelefs faid, by perfons exercifed in fuch ftudies, to differ from it confiderably, by having a greater fpecific gravity, by more effectually penetrating and diffolving metals, by a ftronger adhefion to thefe, and by a lefs volatility. We may find in the books of many authors, who, though not alchemifts, give more or lefs attention to thefe fubjelts, a great number of proceffes for mercurification, or for ob- Vos. II. M taining MER CURIFICAT ION METALS fyiuing Puen of metals ; moft of which are very long : but other faline matters, or fublimation through ufed, and confequently fubje& to aj]. hé - Joye: pig with concourfe of free air, in Geber’s man- che ) oe ET au ke foo ony. she i this latter cafe, we muft look for the mercurial fub- Go eis Chem, ap ions in the metallic fumes and flowers; and if any fuch. fubftance be obtained, it ui Sidendly ronan from the vofiti the metallic matter emp Vidoaia tien tb in the Memoirs of the Academy, that obtaj : he obtained mercury from lead by an eafier and hriplat pro- ! : 5 Ys i cefs than thofe above-mentioned. This confifts in Sho ove ne gl 2 i erfectly fome good nitrous acid with lead, whic iy m o”.. : done effectually by employing more lead than the we can diffolve; and from this {olution, according to Mr. Grofle, agrey powder is precipitated, in which mercury is difcovered. This experiment being fhart, Meflrs. ylee- uer and Beaumé repeated it with due attention in their Courfe of Chemiftry; but they did not find the grey is curial powder mentioned by Mr. Groffe. As the exad@ne Es and veracity of that able chemift are well known, we mu believe that the lead which he employed contained fome ex- traneous mercury, which might eafily happen in a laboratory. The fame thing has poffibly happened in other pomiens ammoniac, and this of mercurification ; and this proves how circumfpe& we i iftille i ing conclufions. Flu cL ad 4 kil ETAL MET SETS ATION, Unter to If luna cornea or Plumbum corpeym be mixed with ap eneral name metal, we comprehend here not only the equal weight of Very concentrated fpirit of fale, digefted to- i properly fo called, but alfo the femi-metals, or all gether during three then an equa) quantity of matters which have the eflential metallic properties, which o we fhall here recount. Thus he Words metal and metallic ill be fynonimous in this artic e. i Cr fofaa fubfonres form a clafs of bodies not very nume- Thefe €Xperiments are important and eafily made, | rous, of very great importance in chemiftry, medicine, arts, not been repeated by modern chemifls ; for which and the ordinary affairs of life. Thefe fubftances have ver other reafon than the fmall hopes of thei f; ucceeding, eculiar properties, by which they differ from all other bodies. thould Succeed, they would afcertain the exiftence of : | P The natural bodies from which metals differ the leaft are mercurial principle iy metals, and woy]d fo much more con, earthy and pyritous matters, on account of their folidity and firm the theory of Beccher, as all the experiments above.. A denfity. Metals and ffones are, neverthelefs, very different, i Praia WW Which that Che- a the heavieft ftones which are unmetalljc being much lighter mift fuppofes to contain the mercurial earth, The conclufion than the lighteft metals. A cubic foot of marble weighs deducible from thefe EXperiments would be, that, by intro 252 pounds ; and an equal bulk of tin, the lighteft of metals, ducing a fuperabundan quantity of mercypis] earth into weighs 516 pounds. The difference is much greater when metals, a trye mercury might be obtained from them, See the weight of fuch a ftone is compared with that of geld, a iw ie. cubic foot of which is 1320 pounds. rs) wher Proceffes for mercurification may be feen jp i Opacity is another quality which metals poffefs eminently ; puthors who have treated of #this matter, particularly jn the opacity of metals being much greater than the opacity of J unker’s book above quoted, in which marine acid is nog any unmetallic fubftance. i . employed, M 2 f a corrofive {ubij uid mercury, and jf fublimed together wit the filver wil] pe oh. d extraneous matter, year to the air, and, laftly, Ir which attaches ; receiver, METALS All metals arein general foluble by all acids; but often thefe folutions require particular treatment and circum- {tances, which are mentioned under the articles of the feveral metals. With acids, , they form neutral falts with metallic bafes. Thefe falts have all more or lefs caufticity, which proceeds from the little intimacy of union betwixt the acid and metal, and from the great weight of the latter {ubftance. The affinity of metals is lefs than of abforbent earths and alkaline falts to acids ; and therefore any metal may be fepa- rated from any acid by thefe earthy and faline alkalis. Alkaline falts are capable of acting upon all metallic fub- 1 ftances, and of keeping them diffolved by proper manage- ui etals car . he) S o Bieht. n a their ow y. F Metals may in general be united with fulphur and liver of fallic fate : ! ir he. A fulphur. With fulphur they form compounds refembling i the peculiar fubftance of ores, which are generally nothing elle than natural combinations of fulphur and metal. Metals have lefs affinity with fulphur than with acids ; hence fulphur may be feparated from them by acids. Some exceptions from thefe general rules, concerning the affinity of metals to {wlphur and liver of fulphur, and concerning their feparation ver, which jg from fulphur by acids, may be feen under the articles of the A mafs of fe. 4 feveral metals, But thefe exceptions do probably take place, mouthed veffel, js fo r contained in , thallow, only becaufe we have not yet found the method of furmount- Pa pet, and the Goreng os that £S Saper Tae WL ns obftacles which occur in the ordinary methods of ence; on the ¢ . Y lenfible pb treating certain metals: of mercury into the fn oR, All ie may in general be united with each other, with, Weighing 3 E i which they form’ different allays which have peculiar pro- perfect globes, T : perties ; but this rule alfo is not without fome exceptions. See ALLAY and AMALGAM. Metals have ftrong affinity with the inflammable princi- ple, and are capable of receiving it fuperabundantly, Laftly, oily fubftances feem to be capable of acting upon which difpofes the all metals, nin metals are eafily and copioufly diffolved by €ras they can, ang oils, and perhaps they might all be found to be entirely foluble in oils, if the methods known in chemiftry were tried for the accomplifhment of thefe folutions. The properties above-mentioned agree in general to all metallic fubftances: but, befides the properties peculiar to each metal, fome properties are common to a certain number ol . of them ; and hence they have been divided into feveral Te Joa a watery Jj Y 0} p pl claffes. 'Sl1quor, beco fur; : 4 Thofe metallic matters which, when ftruck by a hammer, i or ftrongly comprefled, are extended, lengthened, and flat- tened, without being broken, (which property is called M3 ductility ail; ME dultility or malleahil; TALS moft violent and %) and which af, : weight, or other Jou , continued fire, nan fixed in the ho POrTolt ar ible alteration, are put diminution of The metallic mare res £24, er, oy 2 metals. i €y to a rar which are ductile wind, Sontinugd action of cgrec, but which if i fixed in eyed of all the iarcd that 1s, cha rayed by imperfect metals, eriftic prope nged into an ea : ¥ rth tiny lead, Of this kind ar fries of metals, are The metal]; e four; copper, iron metals, lofe ie fibflances which, as well] 2 Ln ve ’ ut which alfo hay metallic properties b s the imperfect from the others }, e Jo ductility nor fii expofure to fire, are five; regulys oF he ham of Tonto are diftinguifhed and regulus Fi; bifmuth, zinc, i) Shets : of cobalt, C matter ne alfo fo far fur- have en FT. Hat it is fuffici i meres, therefore togiveit a diftin clafs we » two of which only w » thirteen metallic hy ub- platina and ere unknown ‘ wonder that thefe regulus of cobalt. to fhe ancients, lati , two : : We have : Platina, Which is a Per Justallie bodies, and reafon to nown til] lately ¢ct metal, fhould have partictla] : ce remained chemifiry Lor. Js caufe to h y be caref; ‘ ope, that if n ‘ renovation of el cultivated, a Btury] hiftory and . s the a . . lences, we m y have been fince the (7) See Nic KE Bey metallic fubfts : as of a blackith-grey col ned the luftre, wi a < with . though itfelf is da taoying the malleability Mr. Fufti pretends that he has 0 / : € contained in yellow mica difcovered 4 . T but when mixed with ne er of that metal, As METALS As chemifts can only know compound bodies by being capable of feparating the principles of {uch bodies, arid even of re-uniting their principles {G as to reproduce fuch com- ounds as they were originally 3 and as hitherto they have not been able to accomplith any fuch decotnpofition upon the perfect metals ; hence, if all the other metallic fub- ances were equally inalterable, we fhould be very far from having certain notions cofcerning metals in general : but if we except gold, filver, and platina, all the other metallic matters are fufceptible of decompofition and of recompoft= tion, at leaft to a certain degree ; and the experiments of this kind made by chemifts, and chiefly by the modern che- mifts, have thrown much light on this important fubject- We may obferve, that even if we had not been able to de- compofe any metallic fubftance, we might ftill, by reflect ing on the effential properties of metals; difcover fufficiently well the nature of their principles. kw The folidity, the confiftence, and efpecially the gravity which they pofiefs in a degree fo fuperior to all other bodies, would not have allowed us to doubt that the earthy element, of which thefe are the charalteriftical properties; enters largely into their compofition, and makes their bafis: The facility with which they combine with almoft all in- flammable matters, and with all thofe which have great affinity with phlogifton, {uch as acids; joined to their in- capacity of being allayed with meagre matters that are purely earthy, or purely watery, which have no difpofition to unite with phlogifton; would alfo have furnifhed very ftrong mo- tives to believe, that the inflammable principle enters largely into the compofition of metals. ; We mut acknowledge, however, that thefe confiderations would only have Rurmifhed, concerning the exiftence of the inflammable principle in metals, but a fimple probability, very. far from the complete proof we now have : but the combutftibility of all metals capable of decompofition by this method, and of the fubfequent reduction with all their pro- perties, by the rejunction of the inflammable principle, furnifhes the cleareft and the moft fatisfactory demontftration that we have in chemiftry. We fhall now mention what is known upon this {ubjeét, and the confequences neceflarily refulting. The deftrutible metals prefent exaltly the fame pheno- mena as all other bodies containing the inflammable prin- ciple do, inthe ftate of combuftion. When expofed to fire, without accefs of air, that is, in clofe veflels, they become M4 red-hot; .much . conteftibly, the phenomena thofe are not th If the inflam In the burning of metals, is - parts, their eflent to the quantity o ta appens upon trial ; for. after calcination, depaits from the meta approaches to the | METALS red-hot, melt, or fublime, accordin they receive no alteration in their ¢ plied in this manner, are afterwards found to be exactly in the fame {tar In this refpect, femble perfectly all bodies which contain no other mable matter than pure phlogifton, ut when imperfe& metals are expofed to fire, with accefs of air, as, for inftance, under 2 mufle in a furnace which is made very hot, then they b their inflamma urn more or lefs fenfibly, as ble principle is more of lefs or lefs combined, abundant, or more Some of them, as iron and zinc, burn with a very lively and brilliant flame ; but this flame is of the fame nature as that of charcoal, of f; Iphur, of all bodies, the combuftible prin u ciple of which js pure phlogifton, and js not in an oily ftate, that is, furnifhes no foot capable of blackening, metals detonate with nitre, 1e circumftances whj g to their nature : ompofition from fire they re- inflam- Alfo the imperfe@ ch that detonation requires are united, See DETONATION 9 NITRE. Their phlogifton is confum- ed by this method much more quickly and compleatly than y ordinary calcination of combuftion heir flame is alfo more lively and brilliant; and and zinc, fome of them, as iron are ufed in compofitions for fireworks, from thejr -very vivid and beautify] flame, itre is alka] the fame manner Lattly, imper “have an affinity when al} ifed by thefe met as in its detonat fet metals be; allic detonations exactly in ion by coals, ng treated with with phlogifton, th and nitrous acids > are deprived alfo or lefs confiderable I acids which at is, with the vitriolic by thefe acids of a more flicient to eftablifh ;¢ in- But we hall fee, when we continue to ex attending the decompofition of metals € only proofs. a mable matter which thews ‘it felf fo evidently really one of thei amine » that ial pr f it ta 5 and this evidently the refiduum of metallic matters, llic charalter, and nature'ofmere earth, The opacity, bril- 4 liancy, ap- METALS ip 3 d ility, volatility, in a word, oo it fufibility, vO differ from tiancy, dudtility, gin metallic fubfiantes ad from all the Property inifh or entirely Sisppens; by their calci- fimple earths, Corn principle; i Ofible, they refeniole them their ied as far as 1 oe mon wit nation has been Famig no longer any thing I with acids mere earths, ir earths can no longer be {ne with pure earths. metals. Thele but are capable of ne) See CALXES Srv called calxes or metallic earths. They are the ion of metals, (METALLIC). e concerning the deeompoliton of 3 prin- We mul ol aan of amma 1. That when on J etals, a fmall quantity ‘nthe metallic ciple is taken from maining part continues I nee formed, and the i portion of calcined net arates in form fide: re with the tadefirored will, ie the calcina- remain uni e of the metals lly hap- of fcales from io Suing without fies, pon the tion has been d to copper 3 or thefe fcales n is performed ens to iron an wl when the calcination i hter than furface of the melted me the calx is fpecifically light as tin, during fuan, et to the very fufible the metal, as i1-metais. fily and lead, a malt of © ons are nek all equa? their phlo- 2. The imperfe le. In general, as mu ient to de- compleatly geletngh taken from them, as TR gifton may be e ey metallic properties; fily be driven from prive them of hlogifton cannot fo eal Ye ft calcination Boron Ore of them. as COPPer, “Tad and bifmuth, may them. Some of th and others, as lea in degree, and mors sh iy rind, bu oy 0 tions of their inflam- be very ea nately the la po lus of anti- retain always oy others, as tin and re eined. but ‘mabe principle ; 21 be eafily and quic TY etals partake mony, may not Sompletely. All the other 2 Co eination. aifo mi FoF thee properties relating tO ehemits, which more or i€ $id » t the labors o t vet made In genera, Ah to be depended upon, Fk malcination of he are not mu ts toarriveat a peric is abfolutely ver atic aban whic bowery is Bll -feveral m arrive at a fee. we can ards fee neceflary, bifare earths, as we fhall afters of their phlo- the nature o llic earths have loft but Lt hey melt and are When metalll xpofed to ftrong fire, d Y ke although Bor to compad males, fill heavy and opake, although reduced to ¢ much lefs fo than th utely unmalleabe, ect, the metallic eafily, and poflefled of aj] ¢ called metal; glaffes. Thefe glaffe Properties of their metals; €xcepting that the heavier than other glaffes; that attacked by acj ds, and fomewhat lefs they are Capable of bein fixed th that the glafles of the femi-metals aro an unmetallic glaffes, Lattly, when the calcination of Metals has beep carried to j height, their earths fi are abfolute y fixed; an re of our furnaces, acids by which metals are chara@erife hefe are the principal changes which metals fuffer b lofing their phlogifton, They are thys changed into fy bu ties, but thofe of earth. Thijs Principle is one of J > Completes the leareft and moft This reduc- ay inflammable d into the ftate of ilitating fufion, is incapable of 5 and if the whole be omoted by a fire gra- ‘dually raife 3 II happen, accompa- nied wi i ich i during which the tinues a certain time, to be encreafed . when the whole has b ; afterwards, cen well fufed, apg the crucible taken rom the fire and cooled, we thal] find at the bottom, upon breaking it, the metal, the earth of which was for the Operation, poflefled of all th i before calcination ang reduion, put into a which: y are fpecifically METAL 5 indifferent, becaufe nifh phlogifton is que Ica it. 3. . whichis to fur the fame in all bo er furnifhing the this principle BR he operation the fu d that it has loft as Laflly, if A we A oy has mived. - phlogitton inciple as the meta fition and the | much of st Pat ER eoiing fe Se oe they are The falts re re retels prove conte nA we do not yet recompofition i earth and phlogifton. he only principles of all compofed o hether thefe two be t 1d produce metals certainly RN affirm this, it Nor which is certainly metals. W hlogifton with ome matt has not been gl this hitherto ch h by combining p le earth. But earth, which has known to be fimpie we try to treat any ters, we fhall accomplithed ; 4 og with Infpmuatie, watisis, we with never been mete fe fimple earths ae fhall even perceive perceive that t : to form metals. Viration and are inca- ~ phlogifton, oi earths refift this CO en have been fo much that the eta n into metal, when t ne nature of {imple pable of eles nearly to approximate . calcined as ve nnot eafily earths. tions, added to this, inion, fo many Thefe copiers only two certain pri callic fubftances conceive how, oo ds as the feveral Ine belief that fome very different It ae capable of inducing ady mentioned in are, feud I added to thefe two aire : ther principle d Stahl, the compofiton of metals. BC iy from the ex. Many great ¢ d of this opinion; and¢ Is, they be- ed O . on of metals, feem to be convince the mercurificati . FCUFY that periments Con ciple exifts CO ine acid, lieve that this oo Dns ; that italfoexi that by extra Qing itis ofa pene its fpecific charaier § or any other body io which 3 ip rinciple from marine mbining it with fimple this mercurial p ioufly, and by compInS rt ren- containing it a acquire a metallic het f being completely Lenin, oe of feceiving phlogifton, an REESE dered capable ility, a different metallifed. ftsadmit alfo, and with pr obabill Y etals, and Thefe Shem etallic principles mn the hich they call mer- proportion © r edcularly the pr inciple hfibly in certain me- believe, that p ore copioufly and fe 1 metals, according curial earth insu The moft mercuria nic. > Moft che- tals than in other ury filver, lead, and Is filver, mercury, to them, are oe from the other metals, and mifts diftingu METAL S and lead; which they call wpjz, metals, curial metal. *lunay metals or mop. All thefe con and others too to the exiftence As marine acid, mercury, arfenic, and €ven the other in which the mercurj is fuppofed to f the Properties 2 arily volatile, 1 ider it as volatile, fince on the mercurification of metals js by {ublimin charcoal in Geber’s g them through manner, and fince foot formed by the met it is chiefly in the als, that chemifts Jook for their mer- Curial principle, then the mercy » but alfo their ut from experience we know, that pb y addition of phlogifton alone thefe calxes may be metallifed, principle is neceff: ary. that all {ubftance inciples of obferved, that this cannot be done. en indeed metallic cal Xes are re fome lof; of quant duced, there js always ity, as the fame wei I Procured which exifted i hat of the mercurial uring the decompofition of the metal 18 not reftored to j¢ by redu » and which ¢tion with Phlogifton alone, But METALS : at if ordinary not as reafonably i - cannot be But may Ye metallic gazthy perfe The difficulty oF Som arths, or ever eeds only from the nt as earth an allifed, this Pro h {ubftances fo bo by nature, mencing hen this pion if ain intimately ifton ore difpofed ftitute it a the earth 1s . uantity of ph & f) from phlogi on ) fufficient q h, entirely free alli with a. 5 any earth, . Ss. an unme metal ; that I as, 1S, relatively to or ftate, as almoft intimately Som be naturally foun 0 earths, or whether earth, whether 1 which we call fimp Y ined. Hence the metallic fubftance Dering fe. than phlogifton, oF . ta hing € >nlv in a it be a me uld be not ? it confifts only . mercurial carth wo ll fubftance, ince to or in a difpo- rather 1s not a ion of phlogifton wit imately with the in- beginning of un arth has of uniting in of the celebrated fition which an ¢ le. This is an idea et of indifference flammable princip certainly cannot fu Pen artificial pro- Henkel, bp the poflibility : i ty : artifi- or increduli ved. the ar duction of metals. re well grounded wk not only pofh- If this option He weald be, hitherto been believed ; + cial production moat than has hiehetto neceffary to be ble, but muc rinciples are, in this ¥ then have nothing for only tof a a metal. We fos moft troublefome of combined ® rei principle, t diftindtly known, and to do i Ee tractable. the re rained. # not all the m ich 1S not even a . we mu no the gxifence oy ing thefe cofifaranions, 3 of the moft But Sue roduction of metals is flexions we fhall add believe that bl Ws in chemiftry. on tation to every difficult proble & will be fufficient de is requifite in that upon this fubjec that great knowledge 18 Tel the produc- fenfible perior pt with any hopes o etal ; they will thew {cience, to Perel soft imperfe&t femi-m ke gold and filver, tion even of ps Ge who attempt to ma even of elementary the folly Oo oliod of any lear chemifiry, of . ' n {> a 3 ca n- without being pe wey defpife ar although eleme chemiftry, which they ce themfclves, 2! oe. {cience, ‘which they Si, in chemiftry, as in ceftary for further tary knowicc 5 fundamental, an : moft ignorant per- the moft tase 2 finoular fatality, t " fee what paffes in attainments. J cefuming. They w ok Sciences, know fons are the mo Tomblics of the Academy 0! with pretenders he PS atirious Society is always bele to his illufts that this il} letallic fubfiay, € general article, dj ces, alth - ‘ Oo Properties m 5 and that ; nl genera) he METALS she laft portions of phlogifton adhere very ftrongly to calci- ‘nable metals, "ome metals, however, as tin and regulus of antimony, may ‘be eafily calcined fo as to be rendered irreducible. By carrying the calcination ftill further, by the methods known in chemiftry, we might obtain their earths fo pure, that all their eflential properties may be difcovered, by which they might eafily be compared together. This comparifon would decide whether their nature be effentially different, or not. If they were found to be compofed of earths eflentially the fame, we might next proceed to compare metallic with un- metallic earths. If the former were found fimilar to fome of the latter kind, we {hould be then afiured that the earth of metals is not peculiar to them, and that ordinary unme- tallic earths are fufceptible of metallifation. The greater the number of metals operated upon, the more general and certain the confequences refulting from thefe would be ; fo that, for inftance, if the operation were €x- tended to all czlcinable metals, and if the refult of each of thefe operations were, that the calxes, when perfeétly de- phlogifticated, do not differ from each other, and are fimilar to earths already known, we might conclude from ana- logy, and we fhould be almoft certain, that the earths of the perfect metals are alfo of the fame nature. They who know the extent and difficulties of chemical operations, will eafily perceive that this would be one of the moft confiderable, Neverthelefs, after having determined this effential point, we fhould only have done half our work. For a k-wledge of the nature of the earth of metals, and where it is to be found, would not be fufficient; we muft further endeavour to find 2 method of combining with this earth a fufficient quantity of phlogifton, and in a manner fufficiently intimate, that a metal might be formed by fuch a combination. We here always fuppofe, that earth and phlogifton are the two only principles of metals. 1 fay, then, that the method of combining thefe two principles muft be difcovered ; for we know that the ordinary procefles, thofe, for example, which are employed for the reduction of metals, are infufficient in this cafe. But this fecond diffi- culty is perhaps greater than the former. When we reflect on the fundamental rules of the union of bodies, we fhall difcover a road which may lead to this com- bination. In fa&, if it be true, as every thing feems to demonttrate, that all natural fubftances may be united to- gether, —— 2s > Decaufe fim ufed without a4 made in furnaces € may indeed facilitate, a4 muc fion of earths, Y the addition of method, which {ucceeds very we tallic earths gifticated ple eart dition, by the fi . h as we pleafe, the fu- {aline fluxes . 5 but thig II for the reduétion ody with another muft be broken, but alfy when this tion is occafioned of facilitated, as interpofition of the par fubftance, th muft not have eat affinity with to that whofe 2garegation jg broken derftood. ' But we are ce Procure the ypjo,, > NOt only the age in the prefent cafe, is fub the body to be united > as may eafily be yp- rtain that all the aline matters be employed to facilitate the fufion of €arths, elves a ver great afin; ty with the inflammable and the greater thig affinity 1s, the more jt ought the tendency which the inflamma} Je principle has ined with the parts of earth. ere then js , Compenfatiop. zlts, while they facilicate the fuf] Principle ; to weaken to be com- For if, on one fide, the on of the carth, place it “In META L 3 : ith phisgiftori 3 1618 favourable ftate for pu piilogifton iii a inoreé favo the affinity of thefe a fition which the bn the other 1 E Fatfic proportion the di Pe . and therefore diminifhes in t f combining with the eart fhould not take phlogifton hers that this combination we need not w intended to be ; arth inten J place. . cafe is different, when She NNR ioufly united Pp But the Cad he of phlogitton, o Pr ih hap- metallifed by h a certain quantity of : i ifticated. For intimately wan calxes not perfectly 5 not only pens in meta h ftrictly united with t ion but it muit this phlogifen, the force of its rion of a new much dimin facilitate very greatly t iy: ofition of bodies Bi Acari blogifion, from the ftrong difp LL. n rcs . * anit wi others of tae i trials of gh Xn 4 by o annot hope to fucce ire not the only re- ‘Hence we canno fe fire : but thefe are ery certain, fiflon Wien h chemitry i 4 daity by nature ar Sores a combinations farmad tk in a fluid her BE En core Fu, Wouter I. is itfclf capable not effefied es es for tha parpats, ol a re ration by the little hea t parts otf bodies, h other, and : he integrant p . i from each o i of keeping t nd infulated f is evidently is broken, fufpe wm of other fubftances, rail zations, Hiofbof earthy 85s fediments, _ftalactites, ye by water. SE n for Whigh #2 Fore aft adinity with phlo- flones of a Il fubftances has the lca ifite conditions as Water alfo of a tly has all the requidit hloifton « gifton, and cont ation of earl "may be a¢- a vehicle, ey from experience er mallifed as well by Laftly, we heir calxes may be metal] that their ) TION. bumpaled, ne the dry way. See ener mtemmediate fub- the Juftnidios by feems to be a very prop llifation, and is Water, then, ¢ firft rudiments of ees ctals, minerals, hen ra for the production of Feeling to the employed by. ound bodies that we fee. nd philofophers, and of all the comp greateft naturalifts a Wheracories ind f one of our g e make in our la x Opinion © ith water all that w annot accomplifh. nature makes w others which we cann ent. . With with fire, and nea and almoft only oh the combina-= Water is het po that is, by the humid w >, : water, therefo ftion ought to be sempt almoft infinitely tions now in q be faid, nature employs d particularly for But, it may b @ of her productions, rene d by che- long time fo 2 ah Can this time be mical metallic So in N Vo L. ‘ > nolecules of earth, of inflammab]e principle? We to be able to affirm 8 upon this fubjed t to have made ents with thefe “vie ; onfefs, I never metals. The infy ave met, have obliged them to multi Ply their experim and to work y pon many bodies befides metals, perties of ‘many fubftances have been thus difcovered fic. efe multiplied difcoveries having been after-. > and arranged, have givenbirth to the philo- 3 to that chemiftry which ceflively ; and th wards generalifed fophical chemiftry now cultivated explains clearly,” whi and which ip thi refearches concern he flow and circumfpe& progrefs o humble and timid > in comparifon of the bold courfe of ancient alchemy : byt experience and refleétion, at random; when, after they h every trial that occurred, witho failed in their attempts ; their return as they came 2 the purfuit tii] the p and fuch is the confequen €n men have long wap ave fatigued themfelyes ut rule or meafure, ce of dered ro e do not confider nature of the {fubjedt, advancemegt of the art for it, have METALS ifation in this article. etallifation in he i to {u eft on m to roduce t Dave Wk a ideas, we Mould ey es chemifts If, in purfuin, f a metal or femi-metal, d admi- h 1g of a f aftonifhment an . rudeft beginnu d much caufe of a : by this , that would aertsioly Fm are we from pining can oo po ration. Muc fect metals, as gold and 1 yrs hopes, method ie parte not intend to a h labors, and to duced. € eo ional plan of {uc them efent a rat dertake t - Js alte to thofe who g wi Na famous chemical ew the dvertife here, tha ifations vertife > metallifations, We ought toa {idered by many as mm s ex- es have been con h is Beccher’s famou procefies ally not fo. Suc which that but which oF he arenaria Jptues BY 3 gold from periment o {ed to the States General to {s of Beccher and chemift Lot fand Such alfo is he = os by treating them any kind of fand. iron from all clay other rov. to obtain i hefe, and many of Geoftroy, to flels. In thele, Iready 0S dip | in clofe veliels. 1 tal that was a with linfeed ol ly obtain me . d judi- -ocefles, we do only intelligent and j fuch procefles, d fand, as the intellig f gold. : arth an ’, > particles of g formed. ayer Se contain fome PL but all Cioqs as contain iron re difpofed to Clays do not in a ferruginous earth, pa e muft conclude, of them contai Soe CLAY, According yw nly reduced or metallia eh, Geoffror's experiment, 1ron 1s only hat Vv Ie c v . 1 that, 4. but is not produced. ur in attempting to give “Th ’oreat difficulties which ga have induced a belief, e gregt of ple earths, ha eafily : ty to fimple ight be more eal R meiilhe 4 i Ae ready Bped might perfect ftate. that the natu fet brought to a MOE pe 4s of al- d the lefs per rincipal objec changed, an ich is one of the p < trials have To effect this, wo tran{mutation, numbe oi of what chemy, and eae have not any certain He Tubflances, we bee ee lpevific differences of on be poffible or not. occafions t ¥ E hether tran{mutation be E eculiar earth, cannot igi {fubftance hy a and con- In fact, if e the earths of the ) the dif- Ly at from eed from efientially CE SC of metals LAY change the fequently i : hs; then, as we {mutation heir earths ; 2 {fubftance; tranim ferences of t . f an fimple us hs and other effential properties tmpofiible. But ’ the SF they be com- of metals oF metals be eflentially the ore or lefs ftrictly De and i this be the only cau: of the in their tranfinu- united, and i Hen fee no impoffibility ir of metals, we : «- Whatever tation. N 2 METALS e caufe of ¢ feems to be Whatever be th he differences of metals, their tranfmutation no lefs difficult than the Produltion of a new metallic fubftance ; even more difficuls, and perhaps it js Alchemifts, whom nothing aftonifhes or embarrafles, beljey i e that tranfmutati We Y> ‘which, as the and by feparating ut very vague and of the differences ake any reafonable IL only advife thofe good principles, to determine ch a peculiar earth, or only one In the fecond place, if it thould be the earthy principle is thé fame in all me- t be demonftrated , s clearly as the identity of mmable principle in metals is préved ; they muft 1 be the only principles in ciple exifts, and whether . it be eflentia] to all metals, or to fome only, and what is ‘the Proportion of thefe two of three principles in the feveral ‘metallic fubflances, When we thal] clearly underflang thefe principal objects, we may then be able i cerning the poffibil conjecture upon thi Who would proceed upon Previoudly, if metals have ea Common to them al], demonflrated that tals, and if tha the infil § matter ; and we {ha € mercurial prin tod ity of tranfmutation ; and be affirmed, we fhall then be the road which we ought to purfye. e have no reafon to be enters into Some chemifts have neverthelefs a faline principle. If that were : true, they would ‘alfo copy. tain a watery princi ple. But all the experiments adduced to provethis opinion 2 . in the experiments, to all trials with fubftances which do not contain, cannot produce any thing faline, do not di {cover property. We muft howeyer €xcept arfenic, fubjeéted and which any faline and even its regulys, . METALS : ich the faline thefe being fingular fubftances, in which segulus, fible as the metallic properties. ediate fubftances are hy foes to be one of oft ite productions be- Ar enic’ . Ime a 1 - ; laced in a : f the pro which enon kinds, and ered potwixt metallic twix ind. Arfenic thus both thefe erties of each kind, roperties common to : # ind func fubltances has p boing either entirely 2 metal o kinds o NIC. i ; even afalt. See Assrg act to a certain degree Upon 1 oii] ithout the concurrence of air, oc rating faline in witl ight tlience cet hat what hap- ethiops fhews, we mig lefs, I do not believe th ] I apts bf chat 1 0 pens 11 es can be deduced. I. diftilled rain certain confequenc fe&ly pure, that 1s, diiti &i ht to be periectly p ht alfo to be perfectly De OE The iron employed ought a d. “3. The water. Sie] very difficultly to be Dr rately clofe d, pure, and iu ht to be performed ina bottle acc nothing to operation oug flured that the air contributes nirg = that we may be aflur on. 4. After the water has r ought he action upon the iron. the iron, the water oug t : {fuppofe a year, upon {certain whether a long arcfully Pirated and examined, os ee tobe . has diffolved any part of the dc that metals do not it really ean time, we may CO nclude d when we confider In the one any faline principle. An oy be nothing elfe fee oe general properties, they oe ately with a large we ined more or le firate that than earths combine Ithough we can demon : fton. Altho g . . and that quantity of De imciple i not in ss oly Bate, oily ap- their : they have ne no more it is pure phlogifton, ftance, that they adhere h in this circumfitance, ftances, and that they pearance, in ueous fubftances, fe chan ime a lobular here Jsh fupported by the a . always a entirely free from phlogiton. {ts, before they fubltar femblance is fo fenfible, tha d that metals con- k This re nature of phlogifton, > ee ow many per fons, new . ev ; : : fat matter ; an or {peak o tained n iy without underftanding its fp well who ae t of metals ; expreflions, whic! Sali of metals the ail, or fa of met The caufe of this qu ” y Sulphur, to Denis of phlogifton Whig A rance merely 18 € . f: ts ave . 3 - : d even fats, ) . their com Pholhopt ails, an principle which caters Jo Bs princi- from the : a property is communicated by pofition : fo N ple METALS : y compound : it. See Prrocringr "hich When i the phlooj with earth phlogifton combines ¢ contains a certain quantity of y matters fo a opioufly and int; | pofes them, that the io metals, it probably © TC itive integrant y fo dif- parts of the new compound . touch each Won, h of the metal, approxi imple earths can, Thi more than the inierer rc and fpecifi : iN fa ty » and ot os of light can pafs 3 at 1s, the fewer fuch i will be; fo that the de as In metals, tributes alfo much to Bodies, the pores of w : ore tranfparent than ranfverfe, or oblique; 5 pores are inte tranfparent than anothe Aterrupted, fo that a bog Lo : . Y may be h glafs is r which is Jef: . Muck more cir cumflances tranfparent than chareon as we fee that opake. Therefo equal, ‘the denfeft ut when other to their denf; right and paralle] Jines. from the prégt’ . both thefe ~. 51o¢ Opacity of efe qualities ; _ metals, th at the begis mes J an eminent Find Probably poffefs and their proper. us article, that the ¢ have feep oper Scie, that the ’ other fubftano ty of reflecting light much Jilin of metals This is alfo felf-evid neceflary confequences of ne than any tranfmit, th dent, becaufe the f; Clr opacity Laftly, he more 1t muft refle@® ewer rays any body can » the dudtil; : denfity,” and from ity of metals proceeds alfo f explained under th ifpofition of their por irom their pearsto comm H e word DvcriLity Pri? as we have nunicate duciij : logifton alfo ap- Ac. all which. fulphur, : ne bodies containing : « c ? ~ hy . - to a certain deoree I or lefs dudtile, at lo refins, wax, volatility of which a] mea the {oftnefs, fulbitity many of them poflef: ais partake Ys an : em poflefs ; take more or lefs, and wh: entirely contrary to tl 11 a {uperior degre 1S, and whic proceed from th hale of Sas earthy ring Propertics refle@ on the come mable principle, [heiple, probably mable principles c FC phroperties of the ean oneral, if we » We thall eafily percejye Py inflam- €ie proper- ties, METALS ties, being combined and modified by each other, ought to roduce the properties of metals. In order therefore to un- derftand all this article, the words EARTH and PHLOGISTON eught to be confulted. The order in which metals, compared with each other, offefs moft eminently their principal properties, is the fame as that in which they are here enumerated, beginning always with that metal-in which the property is moft confidera- ble. 1. Specific gravity or denfity. Gold, platina, mercury, lead, filver, copper, iron, and tin. 2. Opacity. We cannot well compare metals with each other in this refpe&, becaufe it is fo confiderable in all, that it feems complete. if, however, they differ in this refpect, the fame order will ferve for opacity as for denfity. 3. Metallic lufire or brilliancy, The fame obfervation which was made concerning the laft-mentioned property, isap= plicable to this alfo. We muft however obferve, that as, by polifh, bodies are rendered brighter, and that as whitenels contributes much to the reflection of light, the vaAiteft and hardeft metals therefore reflect beft. Hence platina ought to be placed firft, and then iron or rather fteel, filver, gold, copper, tin, lead. ( nt) m) Hardnefs of metals may contribute much to the duration of their polith ; but certainly {oft metals, if their texture be equal- ith than hard ly compa&, are no lefs capable of receiving a poli metals. Some hard metallic allays have been found to be lefs liable to tarnith than fofter compounds, and have for this reafon alfo been chiefly ufed for fpeculums. The property of reflefting light feems chiefly to depend on the clofencfs of the particles, or face, and on the color on the denfity, on the {moothnefs of the fur being moft fimilar to the color of the light to be refleed. The white metals, filver, mercury, tin, reflect light more abundant- ly than others. Gold being the denfeit metal, and perhaps be- caufe the color of folar light hasa flightly-yellowifh tinge, does alfo refle& light very copioufly, Hence fpeculums made of leaf- gold have been found to be very effectual. Iron or fteel reflets much lefs light than any of the above-mentioned metals, althongh the author has confidered it as capable of a greater reflective power. Platina is generally in fo fmall grains, that its refleGtive power cannot eafily be determined. The precife degrees of that power which ought to be afligned to each of the above-mentioned metals, cannot without accurate experiments be afcertained. How= ever, I think, their reflettive powers will be found to be more nearly in the followin order, than in that mentioned in the texts Silver, quickfilver, tin old, iron, copper, lead. ra ' Bg N 4 Fe 4. Dugility. MI 4. Dutili d &i " Ye Gold fil platina 5. Hardnef;, Ee Fay lead, ‘ Tenacity B Th 1) 44 tenac; which the A Tar or underftand ppears t { dnefs. Orrin aco tin, lead, Ty . ¢ fot yet deter. copper, filyer, gold, tin Iron, Platina, tina is not yet deter 7+ Eufibilipy, Mercury 2 iron, and | : fire of ay Platina, whi ine acid . . r. Gellert’ ble contaj d, nitrous 11S no coly mn > and great. Their pay. Hie articles of the feye YEH T (7) (2) Mica, or Talk, is an exible, thining plates. me brite] See Mr. D’Arcep’ © rumple, ap Ica is ejth er rown, 8re : green : micas gener Ce k, d femi is colored, red : The ; : co » chiefly jrop ogeg ’ vilca is therefo .8ypleous corer Ze-g lafs, ] M1LK MILFOIL. (0) | MILK, and WHEY. The milk of animals is 2 white Yiquor compofed of three very different fubftances, namely, butter, cheefe, and whey. Thefe three matters are intimately ‘mixed with each other in frefh milk. Whey is the only fluid Dart of milk Butter and cheefe, which are mixed with it, have each of them a certain folidity, and are not foluble b whey. Thefe two matters, the former of which is entirely of ah oily nature, and the fecond gelatinous or mucilagi- nous, are only interpofed and fufpended in the ferous part by being very much divided. Hence we fee that milk is a true emulfion. Butter com= pofes its oily part, which by the interpofition of its particles gives an opake white color; the cheefe ferves as a mucilage to keep the oily part fufpended ; and, laftly, whey, which is naturally tranfparent, is the aqueous fubftance, which is 2 vehicle for the other two. Milk may then be juftly called an animal emulfion, From its properties we fhall fee that this name fuits it in every refpect. Milk, recently taken from a frugivorous animal in good health, and fed with proper aliments, gives not by chemical trials any marks of an acid or alkaline quality. It has a fweet, agreeable, and fomewhat faccharine tafte ; it con- tains no parts that are volatile with the heat of boiling water, at leaft in any fenfible quantity, foas to be collected. Its fmell, which is peculiar to it, is very weak. ‘This liquor is very {ufceptible of alteration ; the fmalleft quantity of acid is capable of coagulating it. When an alkali 1s mixed with it, a kind ‘of coagulation happens, which is very different from that which is occafioned by an acid. This difference proceeds from the ation of the alkali wpon all the parts of the milk, and efpecially upon the buty- raceous part, to which it gives 2 faponaceous quality. Milk alfo very readily fuffers feveral remarkable changes, without addition of other fubftances. The oily or buty- raceous parts of the milk, being fpecifically lighter than the - (¢) MiLroiL or YARROW. The flowers and tops of the com- mon purplifh-flowered milfoil afford a blue oil fimilar to that of camomile, Thefe flowers have an aromatic and not difagree- able fmell, and fomewhat of a rough, bitter and pungent tafte. The bitternefs and aftringency remain in the extralts made by water or by fpirit. From an ounce of milfoil-tops, water €X- tra&ted three drams and a fcruple, and fpirit extracted from the fame quantity two drams and a half, Neuman, i | reft, MIL xk t weakly, feparate in colledted great quanti Omes acid, and ; milk occafions a he feroyg 3 S coagulated, diftinét feparation of from each other, tion is made, prod ties of both, methods, accord; and the whey a As the acid, which difcovers itfelf in curd]es fpontaneoufly, IS more than js fy the milk when it gulation, and as i flicient for its cog. i e both to the Cheefe and to the whey, milk rally left to curd]e fpon. tancoufly, either for the making of cheefe for aliment, or of whey for medicine, This fenfible acidity ; Mixing” with the milk, b i fmalleft quantity of acid accelerating ths coagulati and alfo grains of ryp. to mix it with the the whey is and the coagulation flow, If e of it, more expedition mga » 1t is to be cut, ini If this may be given, Itis then to more heat more expeditious, » and feroys Parts are feparated ¥ imperfectly, ach of thefe three of the other two. © butter and the purified in the rhanners mentioned yy dey their par. ticular articles, € whey muft pe cleared | ous particles j¢ contains, Jufiiciently, by throwing MILK } f tartar in water, - rains of cream o isto be made by boiling ab REE ; after which the whey is d alfo the white aper. TT. Ife than fit ered through Bw ed 0 curdle milk is nothing hy This The runnet emp oy 4 in the WS It fmells of old a milky all falted that it may be kep ntains a fufficient matter is ufually ulates milk, becaufe it cor kind of leaven cheefe, and Chet uantity of acid. It ation of milk. The but not fenfible g ing the acid fermentatior es, fuch as the capable of produc £ feveral other Asante ee Id fame may be fai i ol thiftles, of wall flower, ne feem acid, flowers of almo “A 11 thefe matters es acidity to milk, curdle-milk, ke. communicate any fen latent acid which and which do Rok undoubtedly from the whey is necef- curdle it very The operation for clar ying whe from the they contain. it could not oerwifs be muft be curdled fary, becaufe 1 es adhering to 1t, w he the cream of tartar cafeous parue ftrongly, by boiling Joie : r mo > ATION. SE white of an egg. hl far from being a pure phlegm. Well clarified whey tery part of the milk, bu foluble . he moft wate y he milk which are ° It is indeed the the parts of the hich be- impregnated ee acenhingly a fenfible ed to nearly in water. evident, when the whey Is and fomewhat faltith. comes Very | ntity. Itis facchar ble quantity of ex- Oe soraimed difolved a confders ine juices, and it i ! harine juices, . In whey is conta f the nature of facc fermentation. &ive fubftance of th f the {pirituous . - ra Be cotsreny make from it a {pirituous drink, o The Tartars § on } ble {ub-~ kind of wine, ins, befides this faccharine fen meptEole d by Whey, oral kinds of falts hie may whey be evapo- ftance, eve e-fourths of ¢ : | place, a cryftallization. LM eo be then fet n 2 cov Phin is rated, and if t of reddifh cryftals will be fo 7 of milk, from certain Toon of milk. Its called the fugar of this color the stfhnatal $8 is manifeftly proc) from the and tafte are extr f the liquor in which the ° drained, dif extractive matter o if the cryftals are well d be much eRe dingly, 1 ized, they will be lized. Accor r, and cryftallize > eration a folved in Ph faccharine. By repeating the op perfectly whiter nd Jol time, the cryffals may be ren : o . Febice and almoft taftelefs, This MIL K ngular nature, well examined, This fat is of afi | caufe 1t has not been . The liquor whj > alfo fone iy which anifhed thefe f contains ng. As this alkalj 1 . efore the above-me Sat fenfibie ithe ntioned Operations, it the mj 1th whi more partic » and confequently whey > more vola rinciples are Ja Siple are loft by expofure to the heat of bo diftil in a nak d fir porated > a_fand-bath to je fae refiduum of ne, phlegm will be at fi; tained, Mr. ”» ft i a piri and afterwards a Ho ah 0 expofi 11! remain in the retort, which oh Polure to air, from the ful; will b mixed. aline fubftances What we ha explanat plr eo 2 together with the lILK, and C ; cles, Burge op cern: or, ning the nature of milk. The Sojgive ud notions con- r, which Ls that milk js of butte 1 ’ 18 an uncombine 1 t 1 d oleaginous matter of t . ), 0 » and n i . ; fecond] ot volatile wi 01 L 2; n Ys of cheefe, which ig a more wy is (fee y matter, in a mucilagj 0 y mn : ginous ftate ; and, whe s €Va- Geoffroy has itron-colored ftly, a refiduous €come moift b with which it is ilk is much employed j 1s foftening, i n ! gs Incraflating : g> cooling 18 proper againft a harp line oro pnefs of hy os again? nel afes are not accompani di Yfipelas, rna fuppurations, phthifis. a a fever ; > mus, and flow fevers, Sj « ick perfons are fr > : : Aueatly dieted with milk alone, but is little known ’ nd requires h : fy : mucg a ; if ; Water to diflo ve it, : 1s reli] ! that i AOE Fail Cp ro interefting "® to thi ed, whic Jl an- a . ay be obtained by es cing the ; Y continuing the © Evaporation be f}i]} d cryflals, fome probably exifts jn tile than contains pn inci water, and therefore nope of Fe ple Its “other iling water, MILK alone, and generally with good effe®. But we muft obferve, that although milk be a food already prepared by nature, and as it were half-digefted, it does not agree with all conftitu- tions. It is apt to occafion one of two very oppofite difor- ders, fluxes and coftivenefs. This is remedied by diluting it with water, or by proper corre&ives, or by chufing that kind of milk which’ fuits beft with the conftitution, and the difeafes to be treated. The milk of goats, for inftance, has been obferved to fuit better than cows milk, with thofe per fons whofe conftitution difpofes them to diarrheas. Whey is not ufed as an aliment, becaufe being deprived of the butyraceous and cafeous parts of the milk which are alimentary, it is much lefs nourifhing than milk. It affords, neverthelefs, alittle nourifhment by means of the {accharine matter which it contains. Like milk, it is foftening and cooling, and may be employed as {uch in the fame difeafes, but it 1s much more diluting, aperitive and laxative. It'is frequently ufed as a vehicle for other remedies. We are far from having concerning milk all the know- ledge which is to be withed. Many inquiries remain yet to be made on this fubje&t. - For befides the falt of milk, which is almoft only known by name, nobody has hitherto un- dertaken a chemical examination, and a comparifon of the foveral kinds of milk drawn from different animals, which milks do neverthelefs differ confiderably from each other, as has been obferved in the Elements of Practical Chemiftry. Confiderable differences muft alfo be obfervable in the milk of the fame animal in different circumftances, and particu- larly with relation to the nature of the food which the animal has eat : for we are certain, that milk partakes much of the nature of the aliment ufed by that animal which furnithes it, See CHEESE. | The milk of nurfes is well known to acquire the virtues of drugs taken by them ; and thus remedies are frequently ap- plied to children at the brealt. (p) MILK of LIME. MILK of SULPHUR. The name of milk is given to fubftances very different from milk ) Thus the color of faffron, the bitternefs of wormwood, and the fmell of garlic, are given to the milk of a woman who eats thefe plants ; and alfo the purgative and inebriating effets of certain fubftances are communicated from the nurfe to the child. Hoffman found by experiments, that the milk of cows and of goats contained more of the butyraceous and cafeous, and lefs of the ferous and of the faccharine particles than human milk, and the milk of affes. . properly of lime. of {ul- parti- See Liver fion, the em on Imonds are des this vegetable > Many plants emulfive or milky moft fluid and volati] hefe natural mil Such an ky juices have not be - exami : much eflentia] kno mination would, h wledge concerning veg Ww : Lek rig P robably find examples of ee milky juices; and this ki ol See Gu g uel light on the nature Jewisd MING ESINS and REsing of refi MIN [0M 900: a vivid yellowifh red eer? OF 7ed lead, 2 flow calc So ed color.” ‘This coloy hy a of lead, of thod of makin a reverberation, Neverthoy begiven b - 1n {mal] quan Aum is not well known clefs, the me- is in commerce TS laboratories, All th i 1t id not made tities of it are T fought from Holland 1 minium which niums op. ufaétured. > Where large quan- fame ployed in paintin Purpofes as the other calxes 2 Zod imgy Wa for all the . ¢¢ LLEAD, ( (4) The procefs by which min: MikAclE fhe following manner b ow nlm is prepared is defer; | €ratory kind, with yy fire J ars. The furnace 1s pny fa rever being feparated “Places at th twelve inches high" the area, or bod . ends ; each fire-place their : he fire. urnace, b el length iy qual to the bre nches broad, ii le furnace, which is E: g¢ cannot fail of s and gum-refins. MOLYBDE N A MIRACLE (CHEMICAL). When a concentrated {olution of fixed alkali is mixed with a ftrong folution of nitre or of fea-falt, with earthy bafes, the. earth is fo copioufly precipitated, thata folid mafs is formed from the mixture of thefe two liquors. As this experiment is fomething wonder- ful, it has been called by fome chemifts miraculum chemicume. See MAGNESIA. MIXTION. Stahland all his fchool ufe this expref- fion to fignify the union of the firft principles in the moft fimple compounds. Inftead of it, we fubftitute the terms combination and compofition 5 which Jee. MOLYBDENA. (r) MORTAR. is about 8 or g feet. The length of the area from one fire-place to the other is g or 10 feet. The quantity of lead ufed in one operation is about 1500 pounds, of which nine parts are lead ob- tained from furnaces where the ore is fmelted, and one part is lead extracted from the fcoria which is formed in {melting the ore. This latter kind is faid to be neceffary, as the former could not alone be reduced into powder. All the lead is at once put into the area, the bottom of whichis level. The calx, as faft as itis formed, is drawn to one fide, by means of a rake fufpended by 2 chain before the mouth of the furnace. In four or five hours the whole quantity of the lead is calcined, or, if any pieces remain uncalcined, they are feparated, and kept for the next operation. The heat employed is that of a cherry-red, and the fire-places and mouth are kept open, that the air may accelerate the calci-. nation. The powder or calx is to be frequently ftirred to prevent its concreting, and when this operation has been continued about 24 hours, the matter is taken out of the furnace, and laid on 2 flat pavement. The cold water is thrown on it, to give it weight, as the workmen fay; but rather (as M. Jars thinks) to make it friable. It is then tobe ground in a mill, and the finer part is feparated by wathing, while the coarfer part, referved for fome following operation, is to be placed at the mouth of the furnace in order to retain the melted lead. The fine powder, which is now of a yellow color, is again put into the fame or a fimilar furnace, and expofed to a very moderate fire, from 36 to 48 hours ; during which time, it is ftirred frequently to prevent its concreting 3 and the powder gradually acquires its proper red color. The minium is then to be taken out of the furnace, cooled, and fifted through an iron fieve placed in a cak. Mem. de P Academie Royal a Paris, 1770. (r) MOLYBDENA, OF Black lead, is a blackifh friable fubftance, anfoluble by acids, capable of refifting the moft intenfe heats in clofe veflcls, It has been generally confidered as a talky fub- flance, chemical inftr ry jos. TUREHE. “Fe nor bell,” b.8 atic i Mortars boyd "ly by percufiion” vel them, and there it - ww; to be poundeq o an inverted fument called 3 0 be Bruck and bruifed bys fue into le motion oj ong in- ftroke of the ft Toyed cireularly le, ooking. =Thofe fub a by rubbing wily. aftl are not capable of bo ver pounded } ' h 1 Traced ftrokes of die : Th are cally pon ly by ih I ey require no bruif; J Fe 1 S mortars are j e chemiftry, infly as of marble co nature of th foie 2 gh, ron, grittftone, and | ance to be po » 4nd agat welCrmines the.choice oa . : ’ Quit, thr a but from fome | a calcinin nce ate exper: i Xperi diflipated g heat fox os veflels, an wy to be deco ments awfon, in hj med; and, long p to be 1 is. Diflertation 1. ng before thefe flammable flowers were rap De Nihilo, € Mr, Quift relates, tha mineral to 3 firo : ng heat ge Ented fulphureogs, fm nd fing - . Q | wers ; the original weight h r. Crona . nure } as i eafil ron and ip, ous fub. are made with Fonals are made i had fulphur ; ang portable furnaces are made of Fors black-lea i rcible hols < } * ucCibles and ack -lead mixed with clay, Black Which it does biol of machines, ity, and a kind of unctuofity of Black ] with this which MUCILAGE of the kind of mortar. "The hardnefs and diffolving power ‘'of that fubftance are particularly to be attended to. As cop- per is a foft metal, foluble by almoft all menftruums, and ‘hurtful to health, good artifts have fometime ago profcribed the ufe of this metal. See DIVISION of BopIEs. One of the principal inconveniences of pulverifation ina mortar proceeds from the fine powder which rifes abundantly ‘from fome fubftances during the operation. If thefe fub- ftances be precious, the lofs will be confiderable ; and if they be injurious to health, they may hurt the operator. “T'hefe inconveniences may be remedied, either by covering the mortar with a fkin, in the middle of which isa hole, through which the peftle pafles ; or by moiftening the mat- ‘ter with a little water, when this addition does not injure it; or, laitly, by covering the mouth and nofe of the ope- rator with a fine cloth, to exclude this powder. Some {ub- frances, as corrofive fublimate, arfenic, calxes of ‘lead, cantharides, euphorbium, &c. are fo noxious, thatall thefe precautions ought to be ufed, particularly when a large quantity of them is pounded. Large mortars ought to be fixed upon a block of wood, fo high, that the mortar (hall be level with the middle of the operator. When the peftle is large and heavy, it ought to be fufpended by a cord or chain fixed to a moveable pole, placed horizontally above the mortar: this pole confiderably relieves the operator, becaufe its elafticity affifts the raifing of the peftle. MOTHER-WATER. See WATER. MUCILAGE. Mucilage is a white, tran{parent fub- ftance, which has little or no tafte or fmell, the confiftence of which is thick, ropey, tenacious, and vifcid, when it is united to a certain quantity of fuperabundant water. It is entirely and intimately foluble in water ; and it does not ap- pear to contain any difengaged acid or alkali. When mucilage is diffolved in a large quantity of water, it does not fenfibly alter the fluidity of this liquor ; but this water, by evaporation, grows more and more thick, and, laftly, acquires the vifcous confiftence of vegetable glue. W hile the evaporation continues, the liquor becomes more and more thick, without lofing any tranfparency ; and this "evaporation may be continued till the mucilage becomes quite folid : it then does not differ from'gums. If thiseva- poration or drying has been made with a heat not exceeding that of boiling water, this mucilage, thus rendered folid, Vor. IL O and MUCILAGE and become 2 gum an open fire, matters are ; they fwell, and firtt are watery, then oily, I$ matter, at the fame capable of being inflamed ; dried, and almoft reduced to mucilage or gum be e veflels, nothing but water js rior to that of boiling water in the retort fee fuliginous, time, becomes black, and is then but not before it is thoroughly the ftate of coal, xpofed to diftillation ip obtained, with a heat not 5 and the matter which re mains ms to be nearly o f the fame degree of dry- ich gradually becomes Pyreumatic. By continuing the ually augmented, 5 little thick kali pafs , and, ] a confiderable duous coal remajng in the oil and volatile a] quantity of refi mucilage, or ucilag s this fpirit will take al] the water of the folution, and will fepa- rate the gummy matter in form of 2 n almoft dry white pre- Cipitate, We may eafily perceive that this experiment can- not fucceed but by adding a fufficient quantity of fpirit of wine, that is, a quantity proportionable to the quantity of water united with the gummy matter, “rom what we have faid concerning the general properties of the gummy vegetable principle, we may conclude, firft, that excepting a portion of fuperabundant pure water, no fubftance is contained which js volatile with the heat of boiling water ; confequently no volatile faline fpirits, 10 efential “oil, or piritus rector, ar leaft in any f{enfible quantity, Secondly, we May conclude, that this Compofed, firft, of a certain qua of {weet oils, which are not volatile of wine; feccondly, of water ; third] in g and, . * h is . that the oil whic attenuated earth; thev are sot and, laftly; o WE XE quantity, AE Bn ap Er Sv or {piritucus folvents; ar -attackable fible. 1 combined in Sifu imi) portion of ol witch i ea! quan- rely, Co ly united with, . ; is in them fo intimately rely foluble in water. gums is in it is rendered entirely {olubl of which tip of ew hat as al compounds, the DC oF union, - > thefe proportions, and in rv matters dre fer- ore fa feeptible of fermentation, all eT hia is confirmed b are iu {or nutritive. . . hi ef] e . e a this refp mentable ; hey of differences, however, xift mn Some of berarixt “the feveral mucous vegetable m very tranfparent, twix A lle gums, . fe ly thofe ca : f only an imper them, particular yt d fufceptible or only ef - coor tritive, an idity or mouldinefs - infipid, bile fo ich pafles foon to vapidity fubftances fermentation, Which paiif h all the farinaceous fu hofe whic a re vifeid, more others, namely t lefs infipid, mor - . ;. tranfparent, ous fermen furnifh, are ber ible of a complet pists iermen Bate ves ticularly when they wee placed 1 1 arti : ER. favourable to fe manmLion f lage in all vegetables, and iftence o : neverthe ee s not equally fenfib ough. ihe vegetable in a orl diftufe i 0 : rally from which n confider it as umive he parts of plants, : - ; lants, or the pa do all impreg fone is ble b ordinary procefes, extractive Fir mucitas ; tractive matter, ilaginous {ub- mfp Watei wits Ah ox certain quantity of mucilag . . | . d faponaceou ter includes always a cer d with the faline an NACHOUS i § mixen w d by certain pro ftance, which remains n en be feparated by ct h might ev Lo f {pirit of wine. matters, and whic a proper application of ff 0 the . : to be in “or Pf the macilaginous pp "the gelatinous : xaily the two fubftances, vegetable kingdom e kingdom. Thefe both of matter in etme. refemble each other, are 1 in er e. . them fngularly nuisjtive ang vided all the plants which i nature nas: Provice even produce h re cecal for join plen 0 “he ents and fupport ave : 1t for a at- ntity o tritivem 2 fuperab un This fuper shandanis " _ in animals, of each Bugg with economy in vegetabies, M8 of the fame ter is reterved w and reproduétion of indivi fof the gen | ing elfe than thing elfe {pecies. f animals are then no 2 duction § of animals odu oak i, ceo epi a provi \ O 2 M-UCTL AGE and nutrition of '¢t heir young. The fame obferyation is ap. “plicable to a]] the feeds and kerne] ‘be confidered zs ¢ sof vegetables, which ma heir eggs 5 -alliwhich ¢ cilage, that it mg ontain fo much py, ¥ be eafily obtained abundantly from them by infufion of boiling in water, : Some of thefe, fuch ag the feeds called emulfive, furnifh eafily by infufion in water a .confiderable quantity of the which we ‘mentioned: above yas tranfpa- nourithing or vifeid 5 but they alfo contain a confiderable quantity of > Which may pe obtained by expreffion alone, The others, thofe called JSarinaceous grains, being bruifed and boiled in water, are almoft entirely reduced to , glue, which js nothing elfe than the kind of mucilage which being Very nutritive, cle grains do n preflible oil rence, that 3 | emulfive feeds, the farinaceous grains, he kind o grains called leguminous, which are very ‘numerous, contain a meal more mucilaginoys than thofe Properly called farinaceous ; ikewi with fubft he roots of many plants are filled with much mucjlage or faccharine matter, Some of them are farinaceous efpe- cially thofe which produce the entire plant, ucilage js eafily obtained from the vegetable fubftances > by infufion or lightly boiling in wate, ntain it moft abunda; » as linfeed, the feeds h ilages, whic fame flate ac in the v From many trees which bein trees are chiefly the much mucijla ge iffues fpontaneoyf] , g dried by the air ang fun, fi orms gums. Thefe acacia the almo nd, the peach, the d even the Pear and apple- ation of nutritive fubftance, which might be ‘confidered as the effet of 2 fuperabundant quantity of nu- tritive juice, rather proceed from 2 ftoppage or too great ful- nefs M US K . is-exfudation pro- containing i y d probable nefs of the i in- the tree, AY Ses iffues, ceeds from hat all the trees fr on onath perifh, with all this mark, the d dry, and do a f nourith- n > : : nt o become languid i" rys which die for wa n ool the appeara many diffe- . ferve for ; ment. cilaginous matters ie s, in dyeing, Gummy and Gums re employed in ne laftoe and rent purpofes. ith water-colors, and for g in painting Ws llient, and foftening nefs to ftuffs. laxing, emollient, larinous firmnefs re the moft relaxing ke the term mucilagino Muscilages icine. But if we take nd apply it, as we remedies in me oft extenfive meaning, a s and faccharine matter in 1ts riety to all the frrmaceout Ri advantages i ropriety, e above-men inc may with p then the a eo utility to us. {ince fubftances, | heir infinite utility > vegetable fu rifon of their tter of our . n compa ief and fole ma . are nothing i ftitutes the chie the orains conititu in it directly from g that {ubftance obtain it ch -vioufly . ther we A t has pre nea ciihaent, tables which we eat, or pt food. e . ich we ufe as ’ and roots of v mals whic to the ani ~ AL). for LF Sez VEssELs (CHEMICAL) MUSK. (s) 11 known : of all know: . juice, the moft odoriferous cenaci- (s} Muskis an animal jul difufive. and adheres very ter \¥7 111s very difiuitve, an irty grains, w Its fmell ithit. From thirty g re of fubftances. fumed with it. antity, {pirit of s perium uantity » oufly to rubles: Ion and from. the fame a oil of vitriol to- - . oe a extra&ted Bios z grains. §pirit of he whole of its fmell, and wine extrattec = The former deftroys the Fh Ic diluted fpirit of tally diflolve HE part of it. Spurit ° spirit of fal ammo- the latter the g ar, have no effect upon it, fcarcely acquires any vitriol, and vinegar of it. Oil of tartas EW urinous fmell. 2h difioives . but extricates from it filled By diftillation tinge from foluble in oils exprefled rr rinciples empyreamatic , : 0 my 1 / Mutik is not ielded the animal p icinally, and as a 1e1dec . dicinally, .. ina retort, mufk Yd falt, Mufk is ufed medic 3 {pirit, a oll, Vola A dilillation of ET enerally hung perfume. . Io fmf included in a hss trating its {cent. y - TN * 8S ol > ~ a {mall portion 0 f both liquor ires little of its : apors © . res lit ha pp a immerfed in it Hoth the fmell and . : w . . uire : c Spirit diftille by this method acq : the fragrance vater Dy tly Improves fo fmell. Butw ion of mufk greatly avender and rofe- inute portion 5s, as thofe of lavenc yo tate. A m loriferous waters, as iferous ingredients, of the dittilled pesiie {mell of other Solitons 1 “Newwmai, thnk communicating any of is own peel : mmun / 0 MUST. 3 MUST. By,, NATR UM frais 1 eptibh, ” A 1S meant the faccharj cularly of grapes, i mentation, is, praperly See Jute Es ( Sac Nz m SL HA, Thi this hit 1s the m i ig i has acquired them ITUMENS, NATR line falt of 7 Is found cryftal (#) Mor NAT Be Haters oF ate N. This is a native alka r marine alkali, which ch lized in Egypt. a which furround produced by the " ; a 5 and as that water con tains other fu]ts alfo, be , be- t a pure min other faline py ri? This falt is faid i531 ln known in this natr ffm, bl | um, fupply all our pipes oF the » é n is no ed with from fixtee n ounces. i a by water, and o Wi ed by fpirit of wi re d either by the yo . taining all the bj aqueous infafion cem to refid jo mrernefs, but not the a ined, con obtained by dilation of a pegs rams of any irh, which myrrh be inclofed ; of a pound of of which may pb moift cellar, th €d In the white of myrrh. If fome yO lar, the Laue : ta har ; powd folved, will extract oF mto which ard bolle egg, and fet trad n ts liquor, act nearly all the Arete yo be gradually re nay be preci y called, o; alte of the ; : s 07 myrrh. um Ly {oluble by nd coagulated by fits 2 gor deliguinm, ur Ir. Rouelle thinks € This co. ton of bitumens anh phat naphiba is formed by a d Y tubterranean f y a diftilla. res. NEPHRITIC juice of feveral king, what CCHARINE) ETROLEUM and NICKEL. NEPHRITIC STONE. (x) ‘NEPHRITIC WQOD. (5) NICKEL. (z) (x) NepuriTIC STONE. This is a green, femi-tranfparent, foliated ftone, an&uous to the touch, not compat, nor capable of being polifhed. By Wallerius it is ranked amongit gypfums; and by Pott amongit calcareous earths. Some other authors more juftly confider 1t as a (eatites, fromits unétuofity, from its partial folubility in acids, and from its property of becoming hard by burning. Its green color is occafioned by copper, 2 {mall quantity of which metal Mr. Pott extratted from this ftone, by fufion with borax. Neuman affirms, that by diftilling the fone, he obtained a {mall portion of an empyreumatic oil, and of an ammoniacal falt. See STEATITES. (y) NepHRITIC Woop. This wood gives a blue color to {pint of wine, or to water. This color is changed to a yellow by acids, and afterwards reftored to a blue by alkalis. Dr. Lewis obferves, that it is the only woody matter which gives a blue tincture ; and that this is the only vegetable blue which is thus deftrudible by acids. (z) Nickerisa femi-metal, firft defcribed by Mr. Cronftedt, in the Swedifh Memoirs for the years 1751 and 1754. The pro- erties there atributed to it are, 1. That it is of a white color, inclining to red. 2. Its texture is folid, and fhining in its frac- tures. 3. Its fpecific gravity is to that of water as £500 to 1000. 4. lt is confiderably fixed in the fire. 5. Iris calcinable, and its calx is green. 6. This calx is not very fufible, but it neverthe- lefs tinges glafs of 2 tranfparent reddifh brown, or jacinth color. 7. It diffolvesin aqua fortis, aqua regia, and marine acid, but difficultly in vitriolic acid, All thefe folutions have a deep-green color. The vitriol formed of it is alfo of the fame color; and the colcothar of this vitriol, and alfo the precipitates from the fo- lutions, are rendered by calcination of a light green color. 8. ‘Thefe precipitates are {oluble by fpirit of fal ammoniac, and the {olution has a blue golor. But no copper can be produced by 2 reduétion of the precipitates. 9. It ftrongly attracts fulphur, jo. It unites with all metallic fubitances, excepting filver, quick- filver, and zinc. Its attraction to regulus of cobalt is the ftrong= eft, next to which is that to iron, and then to arfenic. 11. It re- tains its phlogifton a long time in the fire, and its calx is re- ducible by a very {mall quantity of inflammable matter. Itre- quires, however, a firong red heat before it can be fufed, and melts a little fooner, or as foon as gold or copper. Nickel is contala= ed in the reddifh-yellow mineral, called Kupfer-nickel, which, befides nickel, contains alfo iron, regulus of cobalt, arfenic, and {ulphar. NITRE, or Sa LTPETRE. Nitre js 2a neutral f pofed of a peculiar acid, called xed vegetable alkali. his falt has a fa] NITRE . rticu= . ition, and pa inciple which enters 7° i, (Nrrrous). able pri on of its acid. alt com- rty the compofition of nitrous acid, fatorated with ! ine and cooling tafte . ble matter, > touch any spn ing any . time it does not te without fuffering s which is fucceed- at ee it seisinlh Lb ta) foie kept in a pie Sein is eafily foluble in d no fenfible alteration. re alkalifed, ‘becaufe hes rucible oiling than in cold § iy YY ome mote and moles ¢ it, even throught sory (N12 y one of thofe falts which are more 2 or burnt PE nc the acid of the falt. See by cold than by evaporation. Therefore, iently to deftr NITRE. : Ph) . {ufficiently ATION of : ftrong heat ured, this falt mug be difloly- TROUS), and Devon of being alkalifed bys Cor ¢ applied, that the water may From this Pp Lo and vitrification o belefes of the retain when jt js coq. When f alone, it affifts the A confi derable part, Ee fabftances, >» many cryflals wij] as pure akalis © poffibly remain in the vi OV ITRoPIOa much larger and § i pias acid may Pu to the fufion. i or m quor has been . BE g > the large faces of which 1 are paralle], They are kinds of Prifms furrowed and longitudin, grooves, e acid and alkali, of which nitre together fo intim, ately, that it may be co neutral fale, i ‘ ifton fixed in a : "All thefe fubftances, which hes ombuftible, bo. b lel 3 All t - ee, and which are never accelerate greatly the y paralle 1 certain degre hot and applied to sigs, it compleat, if thefe ing made red-hot a nd rende D3 /, nitre dlalifaion oh en quantity X a eombuttion ances be sthe calci ino of It is not deliquefcent, byt it retains ftrongly i fubfamces much and compleats acid affifts the oy J the water of its cryftallization, by which its tranfparency is § of thefe fubftances, burns itfelf along with t preferved even in adry air, and jt does not efllorefce, or be. 1 their phlogifton, an fenfible de- come mealy, : mable principle. is made with or without any ond the itre is one of the moft fufible falts, Je is liquefied by 5 V This alkalifation ie the ftate, the LL. much lefs than what is neceflary to make jt red, and re. | tonation, according cy of the mixture of hy a oe mains thus in tranquil fufion without fwelling, i oreater or lefs wind thus decompofed or al ais 22 rie thus melted be Jef to cool and fix, wheth c A matters. And the ni d by fuch or fuch fublingon; 2 A red-hot or not in this fufion, it Coagulates into 3 folid, fono.- i quently called witrs fived By nitre fixed by cols oo witre is rous, femi-tranfparent mafs, and js then called mineral . ftance, nitre fixed J b coals. This name i fix refiduum cryflal. This melted nitre, or mineral cryftal, has, ex. alkalifed by tartar of operation is finithe , f nitre, with cepting the arrangement of the cryftallization, all the fame improper : for Vash ue but only the alkali o loved for this Properties gs cryftallized nitre, poe obferves, that contains nothing W he flammable matter employ nitre lofes by fufion little, if any, of the Water of its cryftal- the afhes or earth o tit detiohiis lization, fi e wei ht of the mineral cryftal is nearly alkalifation. mena which nitre enihibits, when | interefling. tite a firft ought 4 as of phlogitton, hie be found under the ’ 0 o not to be attributed to the water of. jts cryftallization, ug is he detail and rss foveral other ‘the cafe with Glauber’s falt, and many other falts, byt is a siticle Dirada 710 of being decompofed by colic acid true fufion from the beginning, and this fufibility of nitre Nitre is capa Co od pure vitriolic acid ative falt ; 1s caufed by the water which enters into jts compofition a5 5 : fubftances. Thefe arthy or metallic bafe; hefo (ubftances falt, and not merely as a cryftallized fa]¢, Accordingly, engaged with a ri acid. But none of I ny docs. mineral cryftal is ag fufible as nitre jefelf, ‘The fufibility of arfenic ; and pholp the fame manner as phlog nitre may alf, probably depend confiderably on the inflam- acts upon nitre in They confifts, are united nfidered S a perfect mable — —- i. only ence it follows €ans of thefe fy. one, ature furnifhes yg with 2 very {mall quantity of nijtre ready formed, in Comparifon of the quantities which are cmployed. Nitre js found naturally cryflaflifed in India, is fwept from earths or ftones with brooms, it js Sweeping of mitre or , Jaltpetre, A p; tre may be rom feveral plans, hefe are the two kinds of (a) The acid of n tilling it with itre may be fe and perh tend parated from its hy, by dif- aps with other earths, . Stah] pre. vitriolated t been deco tllation, The q uantity of yieriol thinks quite too inconfiderable to b which the nitre Is decompofed, fea- falt is diftilled with clay, amuch Jz 8€r portion of it remains undecompofed, Th; alfo ¢ im in his Opinion, that clays do not extricate the acid and fea-fa]¢ Principally Y means of the vitriolic acid contained jn them, as this acid ope- rates no lefs powerfully on the Jatter than on the former fat. ‘He her earthy fubftances, as fand, and ey mployed as the clay is by diftillation, by; wi the refiduum, when clay was ufed, Iixiviatiop . reas when fand the alkaline bafes of the falts mj uum, € concludes from his ex “¢ pofition of nitre and of fea-fa]y b ““ attribute d only to, the divifi ““ of thefe earths; ap $ of nitre place fo ance has more dif. Its without fufion.” natural Eras NITRE . by nature, and : All other nitre is only ga hy required to natural mitre. walls of old buildings. it, as we fhall pro- is found 1p he, extradl it, and to wy reflexions on the CO plait, after having made {ome re bafe ed to : . A in an generation of Siig fle. nitrous. acid, engaged ir sia dy As neither ni here found collecte he marine acids are, whatever, 1S A as the vitriolic a to time in places rial in great quan d oroduced from ime evidently appears but is only found pe this falt exifted ; aids oy A bo be habitually produced by the conc abitu . on. ire do favourable to Jig formpti believe, that Desy a Some chemifts pe! from fubftances long exp: other two 1S commonly Obtained 1 ready formed, : {ited in matters that nitrous. act d that it is fucceffively In uite rejected, mineral acids, an tion. But this OO een affured from proper for “by chemifts, fince they 3 moft proper {ub- particularly ve by a long expofure 0 of nitrous acid, as experience, t ception and retention btained. Cloths ftances for the re Pu no nitre 1s ever © hanging freely, fixed alkali, to he E "and expofed to air £ A) falt; but foaked in fixed a " filled with cryftals of an are indeed Wy ‘o 3 tartar, and not re nt nitye or nitrous this is Vino ate fide, we are Span found but in places On the . fe, is ney oe r anima acid, oF “bing impregnated with vege “inaceeffible ca abie o P, ever foun 1n S. Juices, Hence, WA great halghts or Seip things, and to thefe matters, ounger confidering d by analyfing My, Lemery he oerfect nitre are obtains acluded from that nitrous falts nd animal matters, has dy formed in the many vegetable “fale exifts naturally ich ase according to Er he of thefe two kingdoms, LA "he has given individua it. Int i er nitrous him, the only Foe ine how nitre, oly Behe a {mall upon this fubje ither at firft not percept: afterwards unt- acid, w hich > mals and vegetables, jt fermentation eX- quantity, in on of the air, and by t ei life ceafes. folded by thea ound bodies as foonas tI liable to great cited in thefe Samp although fpacians, > not permanent But this opin oetables and animals d deftroyed. The difficulties ; for veget lly produced an fed, con- ings, but are continually prot hey are compoled, beings, u s then, of which th y d the earth. We A es from thg air and the may fift of princip ¢ N I bje to Mr. at all that we can inf e vegetable matter Si riolic acid tracts with fome other to him, jg phlogifton . oyed by nature to co matter of putrifying and manner for giv acid. principle. This is the moft confidering the ana] nitrous and the volaii] cumfltances atten Proofs of it. Firft, the at or {ome m pofited in Second which ha ding t mofphere 2 atter in which i Proper bafes, ly, nitre is ne ve been im and putrefadtio, is the: method em. mbine this acid with the inflammable fubftances, in the convenient Proportion Ing to it the fpecif ppears to cont t exifts, and T R FE Lemery, tha¢ the nitre found us to them > and pro- grow. Befides, y be putrified without > unlefs they have beep ex- and ftoney matters, the nitre or nitrous they do not even always its production : rence of animal ang duction of nitre, rigin of nitre js that t, with Beccher, that id, and that from this al] hat the nit This principle, accordin C charaer of nitroys For without betwixt the ain the vitr olic acid, from which it is dew ver. found byt in pregnated with vege juices, and thefe jui ong time to ha Thirdly, M hole eflrs. ng time, earths In nitre, after having deprived the No nitre wag formed ip them, becayfe ibed any vegetable or anjmaj juices, Laftly, the Academy of pofed fome years-ago, for the fy $ muft have remain they had not t Sciences at Be bject of t - ed 2 fufficiently putrefadtive procefs, d Lemery hay pure air, during a Jo and fone m of al] € expofed to S very fertile their conten ts, and again im- erlin, having pro- heir anpugy] prize, to ine the origin and principles of TitFey 0 that hav- . Ee btained the prize, S55. acid a salearcous fon ea the pt itriolic acid a gal foun who pbtainec tac pilZ and vitriglic e time, he ing lodked ved it 1 the air during nent 3 favoura le raat i of ne Tp esprit 3 Lou it afterwards full. which Mr. Fietchs, niony 100s d to Stahl’s op er ot ich we have related, . 315: . ch we . Memotr. ; deed of the obfervations a nitre One parti b Mr Lemery’s ReiOn, during their life, as agrees te a. vegetables ‘and animals 8 principles of thal be ProduSen in Vege 2 her 4 GRR acid dif~ Lemer y Hales fof afterwards iy she d ftones, as Stahl fubftan Ges <0 or pre-exifting in Nii; that. nitre does; not fufed in the air, certainly be inferred, © in nature, 3s the fays ; this may ed, and in great quantities is generated and exift ready Frm acids do, but that currence of circums vitriolic a9 m time to time by the con | iy uced fro po ation. {Ag an ps favourable to its Ie abject oF the prineiple that bferve upo: LY s we have 1 v tion of the nitrous qcid; tha fo its formatiot, 2d =» progucion rs are requill {ceptible of pur putrefaétive Sperm fubftances are alone pert I the three vegetable BEA acid therefore belongs equall ; trefaction, 1 aoed : neither kingdoms of Bate commonly found sifengag Ss. as marine Nitrous acid 1s ith any one particular bals, 2 s with : ed with a y combine ida 1s it generally nice fooner generated, Hanii en are within acid 1s ; but 1 hich it can diflolve, an united with a fixed any Accordingly, it is jometimies LAID {uch are what - ra d confequently forms oma the nitre of plants ; alkali; an ings of nitre, and the {forbent earths, the {weeping ined with abfor . are called it is combine it is formed ntly it nig) here 1t 1s : but moft I thels in Dat sencrally fourd.ip becaufe it Be . it is, therefore, no 5 ou . . ; 1S. , . mel oof nitre with earthy bet production of ae hrs the fo ble places fo icularly fuch rable p . d particularly The moft favou nd animals, and p houfes of tations of men anc kitchens, tables, the habitatio ift, as cellars, kitc ’ be impreg- mol . : apt to be P 81 210 JO A of that kind, which os ond alfo to have Hes 2 °vesctable and WG matisray to patrsfaliios nated with veg hich is favourable hich might . ure, wi whic 15, an habitual mag ‘are {heltered from Fin, foon as it is 2d, he iDolve and carry off the ni otherwife Thefs formed. copper cauldrons, j it is fufficient] nitre and ¢ cryffallizable b only; the com tion, and form bottom of she NTTR$ Thefe buildings are ¢rye nitre-beds; Wen gp their rubbifl an plaft cr are full of nigre : bu only a nitre with 2 Nl €arthy bafis, which is Cryftallization or detonation, whic a qualities in nitre for the principal ufe cable, and which jt cannot bafis of fixed alkali, Bef; With much commen falt table and anima] matters 3 a perfect nitre, ali, and to dif. which alter jis d in the following . The rubhifh containing nitre js Pieces, and’ mixed with early an eq es. This mixture is to be put cach other, placed vertically on one ported at the height of two to be broken to fmall ual quantity of wood- nto catks ranged alop of their ends, and fup- found. At the The lixjv ium of nitre thus prepared js carried to great ch i y ftrong for ¢ two cryftallizable ommon falt, t 1s boiled and €vaporated, ti]] he cryfallization of the fats, falts contained in this lixivium are and as the latter of thefe falts js Y evaporation only, and the fecend by cold mon {alt cryflallizes firft during the evapora- s fmall cubicy] cryftals which fubfide to the cauldron. The 1; t- Petre-makers cal] it the ‘hey take it out with large bafket hy; ladles, and put it in a '8 over the cauldron tq drain, This evaporation is N1TRE ' as it oo way as faft as i § ain is to be taken 2 hat, when is th be fo much eva orate in order is fore eh nitre‘will > Td for that pur- itis cold, it 1s fufficien . ITY ut from time to difcover when It it is to be taken out fr that Be i en, time. ‘When f mitre 1s forme an 12, which . tity © \ opper bafons, whic a fufficient quanti uldron into large copper bal or ‘the liquor o hen defigned for ji cr yRalizution quickly they carry to: tains thuch nitre, an 1e bot- ~As this He Spare of the falt SRI ty ‘eooled, the greatelt nfhapely malfles, comp f laroe tom of the Hike cey fils of nitre, and pete are called ick feel wi on their furfaces. Thefe regular cry vo . . the nitre of pis fons remains a large ramrey nd fecond bi “which cannot be cryftalliz od in the fame man- Cn Ee hatone pe nr! operation aril. ead uote mitre In ae by cooling the fuses ab ie ill no more nitre can be forme red and acrid, Is repeated a which then becomes very : evaporate -water of nitre. . f nitre and is called iy Jectoer ie wl A see o v pra This moer. ith earthy bafes, which been mixed ie opin hy a quantity of alps paving De mother- ceed from too } of the nitrous rubbiih. fufficient quan- with the lixivium of avoided, by mixinga fu fe all the water may ee rubbifh, wo GLE col after tity of athes fes which it contains ; ing would falts with earthy Sas and cryftallizations, nothing 4 with the feveral ev ol quantity of red liquor impreg remain but z . loved, the wn Rous ole the ufual quantity of. fas other of “nitte When on falts contained in the moth m. ‘This bafis of the oy by adding an alkaline fof wives and, sag beigreeing hite, and is called the magnefia the mother- precipitgee fs win the nitre with carthy babs of fixed alkali, gt tae tam nged into a nitre wi! falt-petre- When, ie by Siyfalleation hd we he mo- is ealily o loy any of thefe methc bbifh after makers do hich they ron on he nisngus "Some time ther-water, fted of its falt by lixi fang manner 85 it has been exhaufted ¢ this rubbifh in the fam .. and lixiviate this ddition of afhes, an afterwards, they that is, with the addi ive that this he lo " ik nitre. We may eafily perceiv operatian ‘obtain rive { of Sciences given, in the Memoir ation is _precifel Niner Ls role | Fars A EEE Cp tre . in ’ : ws foiled by the Tropes BY thefe cryfialliy a; of alf that cols q vy In which ;j zation Eryftillize by cofg cryltallizes alon $ is red d, ; .and by proceeding 2 In this fecon le I= an, falt, and to falts wi than at firft; fo that i f_ the nitre yet fufficient] | 2Un-powder; and it mult there, the prepara. : or + ] : . allization, This js the op rid : It is ver b fl ently pure for ay ] herefore undergo a he theory of a confiderab]e : i ue or r Petit, who has q ancit ¥-of comme cicription of the Ei quantit Af y of common ourth part of the us quantity of pj il we Comprehend ¢ 2 a A the mother- wate, of ni tre ! This N1TRE - This common falt is depofited in the nitrous earths and flones by the vegetable and animal juices which are neceflary to the generation of nitre, all which contain more or lefs common falt. The exiftence of this common falt in all nitrous fubftances has induced fome chemifts to believe that the marine acid ‘was converted into the nitrous. I have heard thita certain perfon had the fecretof transforming com= mon falt into nitre, and that he had propofed to furnifh nitre at a cheap rate. ‘A moré particular examination of this matter deferves to be made by chemits. : No ule is made in France of the common falt in the manufacturing of falt-petre. "The farmers-general oblige the inanufacturers to give an exalt account of it, and to throw it into the river. The purification of it would be difficult ; becaufe, during the making of the falt-petre, a febrifugal falt of Sylvius 1s formed by the union of thevegetable alkali of the afhes, with the acid of the marine {alt with earthy bafis; and becaufe the falt of Sylvius has all the properties of common falt, only that its tafte is very difagreeable. The ufe of nitre is very extenfive in medicine, and inthe arts, and in chemiftry. = Perfons who know little of che- miftry muft be furprized that this falt, fo inflammable, fhould be employed in medicine as 2 powerful diuretic, feda- tive, and cooler’; which virtues it certainly pofleflfes. Itis daily prefcribed by the moft fkilful phyficians, from ten ot twelve grains to half a dram, in fome proper drink. It might be given without danger in a much more confiderable quantity ; for this falt, which is perfectly neutral, is very mild ; but it has been obferved to produce its intended effects better when it is given in the above-mentioned quantity only. (?) (4) Some curious experiments concerning the effects of nitre taken internally are related in Mr. Alexander’s Experimental Effays. From thefe it appears, that nitre has a power of almoit 1n- ftantly retarding the velocity of the circulation of the blood, and of {uprifingly diminifhing the number of arterial pulfations ; ana that its effets are much more powerful, when newly dif- {olved in water, than when it had remained diffolved during fome hours. As this difference muft have proceeded from the cold which is produced by nitre during its folution, probably a much greater effect would be produced by procuring that folution in the fomach. A remarkable inftance is given in that book of a fud- den fwelling over the whole body of a woman, and other dan- gerous fymptoms, which were occafioned by her fivailowing a fo- lution of nitre-in water, by miftake, inftead of Glauber's falt. Vor. IL. P Beles NI TRE Befides the nitrous acid obtaj i ained from nitre, which i Spay agents in chemiftry, nitre ers oo alfo ; mical operations. Its properties of d nating with bodies containin ao ith ntal g phlogifton, of i ee Sleigation, ad particularly oe fo im als, render it ufeful for the purificati i PR yeu, tend, he purification of gold nd filver y are allayed with othey ] hutre 1s quickly and eafily alkalifed, it enters i i , ! . ters int - gofition of seducing fuges, or a fimple au ail incation. Laftly, by its detonation i be employed to difcover the Sa of the inflame ab] principle in fubftances. Hable ut the moft confiderable ufe and co i ok onfumpt itr J SA % gunpowder, of a dl | reat part; and for this purpofe it muft nn pofe 1t muft be ver Sid ee POWDER (GUN), and Powpkr (FuLMINA, - are E (A LKALIS ED). This is the fixed alkali which remains after the nitrous acid has been deftroved b its detonation with any inflammable matter. This alk li J genedlly called fixed nitre. See N1TRE (Fixep) ae i PERE (AMMONIACAL). This is a neutral 5 refulting from the combination of the nitrous acid, to ¢ point of faturation, with volatile alkali. See Amn NIACAL (Nitrous) Sarr. Hes : Tony fCALLaRPOUS), or NITRE with , | S. Calcareous nitre is E go of He Tiasous acid combined to aturation he -areous earth. tis generally called nitre wit bajisy becaufe the falts formed by the ae kd ey i earths have not been attended to. ; oe . Nitrous acid difiolves with great a&ivity all ] gars and ftones, calcined or Seloand” It diffolves a arge quantity of them, and leaves no refiduum when the or pure. By this combination is formed a neutral falt ys eliquefcent. This faltis not fufceptible of a true cryftalls, Peden: It has a poignant, acrid, and bitter tafte.” If jt ¢ evaporated to drynefs, it becomes folid, and feems to be an earthy matter, which does not detonate, or at leaft ver weakly: with inflammable matters. - thefe properties of nitre with an earthy bafi fiom the weak adhefion of its acid to the on fg ee eon is fo weak, that if the falt be diftilled ina retort, an acidulous phlegm will firft pafs over; and when the fd is encreafed, all the acid will follow, excepting a fmall portion 2 which NI TRE which adheres more ftrongly, but which may be at laft ex- pelled by calcination in an open fire. Mr. Pott, who has particularly examined the combination of nitrous acid with quicklime, fays, that this acid fuffered remarkable alterations by diftillation from quicklime, and by repeated cohobations. By thefe experiments he obtained a nitrous {alt more fenfibly fufceptible of cryftallization and detonation than ordinary nitre with earthy bafis; which is and may induce us to fufpect that a part d, and of its inflammable principle, might combine with the quicklime, fo as to giveit the character of a fixed alkali; or that the nitrous acid, deprived by the quicklime of part of its phlogifton, might be rendered more capable of contracting a ftrong union with the quicklime. From what Mr. Pott has faid in his Differtation, the nitrous acid feems, by treatment with quicklime, to be rendered fufcep in the 2-178. A great quantity of nitre with earthy bafis is found ready formed in nitrous earths and ftones. Nitre is moft frequently produced in that form. This nitre may be decompofed by a fixed alkali, which unites with its acid, and precipitates the earth, in the procefs for making falt-petre. "I'he mo- ther-waters obtained in thefe operations contain ftill a large quantity of this nitre with earthy bafis. See the word NITRE in the preceding article. NITRE (CUBIC or QUADRANGULAR). When nitrous acid is faturated with mineral alkali, a neutral {alt is formed, fufceptible of cryftallization and of detona- tion, and confequently is a kind of nitre. This falt has all the effential properties of nitre with bafis of fixed vege- table alkali; but the marine alkali, which is its balls, changes the form of its cryftals, which are not channelled prifms, like thofe of ordinary nitre, but are cubes, or fome- times parallelipipedons, with rhomboidal faces. From thefe forms the falt has been called quadrangular nitre. We may make quadrangular nitre by combining directly the nitrous acid ‘to the point of faturation with the cryftals of foda, or by precipitating with this alkali the folutions of earths and metals made by nitrous acid, or by precipitating with common falc the metallic folutions in mitrous acidy which are fufceptible of this precipitation ; or, laftly, by decompofing common falt by pure nitrous acid in the ope- ration for making the diftilled aqua regia. In all thefe cafes P 2 the very remarkable, of the nitrous acl tible of an entire decompofition, See his Differtation French edition of his works, by Mr. MACHY, tom. IIL. NITRG ER evidently combined with tre. This f3l¢ is not ufed rts, as jt f the nitrous acid is and forms cubic ni chemiftry, or the a to ordinary nitre, NITRE FIXED by ARSENIC. Th is the alkali of nitre, the acid of which hag in an open fire by means of arfenic, of wh;j fome portion is retain m iS preparation been expelled ch, therefore, © make this pre- Is to be put into crucible, which js furnace, When the p; ed by the alkal;. Tr paration, fome nitre ; £0 be placed in 2 {poonful of white ever, different. burnt and deftroyed 3 but j difengaged from its bafis by ic which has that property. The ebullition mentioned is caufed by the powerful action of arfenjc Upon nitre. The fumes which rife copioufly in this operation are 3 mixture of thofe of very concentrated nitrous acid with a part of the arfenic whichis fublimed by the hear, Arfeni C is thus projedied at diffe le, till no more effervefcence ig operation §s finithed. The fumes which rife noxious, and therefore jt ought always Imney which draws wel], ngage the nit wit expect to find in the crucible, after ion, the alka); of the nitre perfectly faturated with ic. N everthelefs, the remaining matter js very alkaline, very far from the point of faturation, carfenic. The cayfe of this is, that ch the air and the vapor of the coals make moft of the arfenic fly off as faft as it combines with the alkali ; for when the evaporation js made in clofe veflels, the alkali of the nits e is Neutralifed, apd entirely faturated with arfenic, §., ARSEN NICAL). ALT (NEUTRAL Asp. Nitre fixed by arfenic ca ains a certain with a ma] portion of nitre wh the arfenic towards the end of may be employed as 5 flux, s» and then the in this experi- the operation as 1t powerfully aff tion, ~ N I T R E . entioned in Mr. Pott has done in his experiments menti tion, as Vir. 1 : d Br 1 GOALS LS AA Nar by coals, the prope : oy fo large that the ni- or ai . i t to 1 1 : le, which ought to | ble is ta De hall A a {mall fpace I ae ) melted tre , : and w : Il kindled fire r half a dram)" be placed ina we 11 fpoonful (about a dram o it. In- and red-hot, a {ma DP rored is to be projected upon it. 11 . tinues ti of charcoal grofly powcerec Bappeths ric antly a ; tirely confumed. . f charcoal all the charcoal is en cafes, another quantity o be con- mation or detonation - du on it, and is left to be till ike the forme i pojted upon sud nlf tr So ; an fumed ; detonation is caufed by it. cible, which at firft * Phen the matter contained a De k and almoft folid, be- . s afterwards thic lefs fufible than EO hen fred alkali, which is much lef this caufe it is be el be encreafed fuficianty eramations “kali melt. During this fafion, fome foned by a portion alkali me I time to time, which are occa oo the want of happen which the large quantity of alkalis a referved from" of ity towards the end of the Ah in good fu- ui Is. When the matter 1 {mall bits the contact of the coa happens upon projecting vy d Eoin of cant, ad is finithed. We cught to uantity of hae Tobie that when the fioest Po ed. i tus: Jubject, is intended to be co Tal the nitse indars ok er to be neceflary for a muft be “ : itre. In this cafe the alkali is 0 wy long ofticatad. unlefs it be afterwards calcined a gifticated, } dephlo- time 1n 0 na it is intended to be 73 fick depnls g : a, ted oe offible, and incapable of 8 erfect purity from gifticate tafte or fmell ; and if its pe the preparation any WA nitre be not required 3 fie T. r or the deto- decumgol ought to be ufed than is figes er is alfo on he whole Sonny ” pe by all other Naan n | : lkalifed by tarta an Apel th piise gH ArkaLri (Fixep VEGETABLE), e . 2 ONATION of NITRE. TALS. All the me- NITRE FIXED iy ME ofition being NLT ich are fufceptible of decomp ated tallic fubftances which a 3 treated and burning matter NITR E treated in the fire with nitre, alkalife jt, 5 tonate more or lefs fenfibly. "The moft ing fubftances, as zinc and iron, make with t nous and fo brilliant a detonation, that they oufly employed for that purpofe in fire-works. uftible matters are lefs effe@ual, but their i with i with the earth of the calcined metals. that nitre is fixed by metals, as wel] as we by coals or by tartar, After the detonation of nit be eafily obtaine d alone, and feparated fr earths, by lixiviating with ing and eva water the remainder, porating this water, this kind of fixe b It is eflentially the fame a5 nitte ammable matter, only that it jg cauftic, and refembles thofe alkalis d with quicklime. re with metals, its alkali ma which have been treate In fome known ope this caufticity which the j € acquires after deto- nation with metallic matters, Such are the operations for diaphoretic antimony, and for the tincture of metals, or /;/ly of Paracelfys, in which the alkalifed nitre is rendered exceed- As, on the other fide, becomes ‘ic calxes act in general upon alkalis as quicklime does. veral metals, See the articles of the fo- and of ALK ALY (FIXED), and DeTonATION of NitTrE. | -Ware, or mney, and it is to be It kindles around the charcoal, matter firft in- creafes, a thick med. The red over the veflel, nation gradually diminithes, melts, boils, and ‘flows if this be not {ufficiently large: then the deto nd make it de- ammable of thefe his falt fo lumi- are advantage. Other com- nflammation the eflentia} this inflam- € may then fay fay that it is fixeq om the metallic d nitre may NI1TRES ri and at laft ceafes. The a diminifhes, and of tartar mixed tog d by ‘coals, are each Alas ly as well as the pis Si Lowers, fol leh This a > d good. ney arc, decompofed, of thelft yery Pe Rertle quantity of De oily when a to contain a he matter not burnt, pac it may be com- ful of 10fpmmalis 7 prepared at once: Duel by treating fiiall quantity ony ©] Proper calciaetion, (FixEp VEcE- greatly sani fixed alkalis. See ALKAL hh them like ‘ becaufe the TAIZ). d by tartar is alfo called ee fufion of Nitre fixe V of this alkali is to Ba operations, moft frequent Mic matters in eflays oe ure. See FLUX ores and meta ofcs it needs not be Joes re . for which PLY DETONATION Nee, TRES with CNITRES (METALLIC) or NITRES ie N ASES. RS e ith a metallic METALL ofod x the nitrous acid A be dif- tral falts So the feveral kinds of thefe f lead, of mer- Be by faying, nitre of filver, nitre 0 . 3 e C- Sy it rt a remarkable differences, pe tallic fubitan > f the metals. diffolved in on the peculiar Aes Land platina, Enos be ond require Some metals, a Bion by nitrous acid a pps and regulus their ftate of aris acid. Others, 2 and are fo well the Se attacked fo powerfu 2 oon as they are of antimony, d by nitrous acid, that, A which feparates dephlogifticate 3 duced into a white y Ey fe they want diffolved, they 4 q cannot remain unite 2 ith nitrous acid from the acid, =a marine acid combined yy on thefe metals, phlogifton. 2 the a&ion of the latter ao: phlogifton, moderates uc lcination, preferves a part 0 hich they remain Du a {ubftance by w ; and thus 1 ; id. : fily folu- united with 4 nitro. ” copper and Jon, Se 4 4 y the Other metals, 1 lone, and remain ary to diffolve ble by a quantity ns I peospays part oF acid is in m when the aci 1s lx, and the the metal: i vicipitates in fig o Sa an Jn thefe metals : il united with the 2 nd not, or very part, Tio falt, very deliquefcent, 2 perfect neu ’ : Lafl little cryftallizable. Py Laktly crete oil were ex and is called o;/ NUTMEG. | metals, particularly thofe called 7v44, or lunar, {uch as filver, lead, d even regulus of arfenic, they faturate, a; addition, but form of cryflallization, Nitrous acid adheres fo ftrongly to thee metals, that the metallis falts formed by them are fufceptible of detonation, but not fufficiently to refift the aQion of fire, which expels jt without the help of any intermediate fubftance, he nitre of filyer ; $s known by the name of lu ¢¢ CRysTALS (Lunar). Me : reurial nitre js 5! | + This fat refemble nitre of filyer by its principal properties, he nitre of lead has this peculiarity, that i ition of inflammable matter, it decrepitates and even inflames and detonates, This pheno- menon muft be attributed to the phlogifton of the lead which 1s the bafis of this falt. Much danger therefore attends the €xpofyre of nitre of lead to f | nitre of bifmuth re in clofe veflels, Probably the » and that of regulus of ar hibit the fame Phenomenon, femi-metals js a Lattly, the other nar cryftals, fo frequent- $ much the See MERCURY, by expofure to fenic, would ex- as the phlogifton of thefe two € as that of lead. s inflammab)] NUTMEG, (,) (¢) Nurmecs. This fruit contains two kinds of oils, name. ly, a grofs febaceous oil, and a volatile eflential fluid oil; i 1 egsrefide. The 3 ore. of which is fo diftillation with {pj- derous, ‘that it finks iftilled with Sixteen ounces of ce of eflentia] oil, febaceous € water in the fil], tial oil, and a part of the ex. preflible oil, F utmegs nine drams of con- is oil contains confiderable oil. It is brought from India, in form o of mace, the mace being one of th ¢ nutmeg, and containing fimilar offs, ortion of the eflentia] cakes, : e exterior co. Neuman, Verings of-th OCHRE, x (dd . OS EoL0s MUNDI. (¢) . A FA ALBA. (f) be defined 2 compoung OF Oil may in general } € a hich is capa- 01%, if at all, foluble in wate d with fmoke and boty, lists, 3 vith a flame pa after its diftilla~ ble of Lie Pt Jearing a refiduum of coa foot, and o y id, water, and iON. {ten, acid, ’ tion. ofed of phlogiften, ac the decompo- ~All oils 1 el elles are difeoyeisd 1 ¢ perhapt the geil ; dor lif il, as we fhall foon f ig? ‘combined to- fis of BY which are in oils i em com a in the ftate of an acid. ; oo gerne | i earths, or calxes of va- s are ferruginous f have been de- (4) Ocure, ares. brown. They — in the fame rious goon, rans or vitriolic waters, pofited rom fe: is precipitated from : ‘a reddifh or yellowith poe ors air. By Jauney as on in vitriolic acid mere) iinable matter, a con- {olutions of ny charcoal or Sei 1m eafted from thefe ie reduction Ws . f iron may be ext ochres is of the ) derable quandity of the iron thus obtained ng Ochres are ufed Wallerius fays, +. that is, brittle when ire a red color. See kind called in: they all acqui 1 ts. By C : It As pigments. . . See Opal. Ores of pax. Munnbi is a variety of the opal. has this pecu- (e), Se its color is generally yellow: in water, it becomes is opake, an that by lying fome hours Some are faid to ac- liar property, nd of a yellow amber pros ora .. tranfparent, B eans a luminous flame color. When retified fpirit uire by this m or OFra HeLmonTII. ile alkali in water, (fF) Ores Biss; + folution of mild Rose alkali to unite “ .x . . n - of wine 1s adde nger difpofition than. th with the alkali, the fpirit having 2 WE) no difpofition ha ati, thus preci- with the yah kali from the water. fixable air, acquires a precipieates : ald or combined bi from the common mad itated, being ’ is not differen Hel- pitated, ate, and isn alba, or ofa Hei i or co TE Oey aioe etic fire concrete vo ipitation is effected by ac de with quick- i fuch precipiisiios lkaline {pirit ma ; montii. No ic volatile alka 3 tile alkali has to of wine to i which esuitic vols of mild volatile Eh water is {fo much firorger tained in a concrete unite with wa nnot be ever . mer ca alkali, that the for VOLATILE). From ftate. Ser Arxar: (Vo From wh O11 , t we h . this fubftanc ave faid concern; is alfo one of id "i 0 confiftinf jo pature of ofl ani J Ximat . v rinci 3 animale. The off tre Buncble of ll veges fg kin dom, Bon betwixt them and ‘th n be ewn. § 0 mineral} can th ofe of the miner All th ee KINGDOMS e fmalleft partic] ral . ¢ oil obtained fro © of oil nces has a certa: rom vy ® n num MS 1ts charaller a ar 3 general pr All has lis that is the > Hi€y may b 5 The heat neceflry tg ldered . . . Y confid All as a volatile body, 3 accordingly oil may Yes oils which ar them, are eafily ; € expofed to a heat inflamed Tt Rabie, Open Sua of evaporating accompanied with fol. on 0: ith 2 white. Tor adh of any Dodies, are ent; e. Qils, like al] nous flam bin, re enya hte om prissiles. oil thews that phlogifton mation. This e inflammap) IS one of its chemifts ( able property of o; gave the own to the ti y oil has Pars oF oil : 1 enn er body witho . fn to be oil. ut being preyiouf] at firft a’ lige es the principles or ¢ +. (&) Befid in the text, we wer Conflituent parts of oi] y mineral acid : h menti ; 8S, € 5 > ntioned a kind of fixable a mit ir, O1L empyreumatic quality, fo much ftronger as the heat requifite to be employed was greater, This oil is always accom panied with an acid, which becomes more and more ftrong as the diftillation advances. In the retort a fmall quantit of fixed and refiduous coal remains, This coal, and Al the foot of oil, are very difficultly combuftible; but at jength their whole inflammable principle may be burnt :. then nothing remains but -athes, which, when well wathed from any veftige of fixed alkali which they may contain, are a pure earth. If the oil in the receiver be examined, we fhall find that it is lefs in quantity than the oil originally employed ; from which we may know that a quantity of oil has been decom- pofed by the operation, The water, acid, and earth evi- dently proceed from the decompofed portion of oil. Hence all oil contains the principles mentioned in the definition. This is further afcertained by rediftilling the’ fame oil, by which another portion of it is decompofed, and the fame principles are obtained. By repeating the operation a numi- ber of times, the whole oil may thus be decompofed into water, acid, earth. The phlogifton of the decompofed oil is diffipated in infenfible vapors, which cannot be confined and collected, excepting that portion of it which remains fixed in the refiduons coal. An important remark may be made on thefe repeated diftil- lations of oils, which is, that the undecompofed portion of oil which pafles over into the receiver, becomes by each diftillation more and more thin and more volatile. Butas oils chiefly differ from each other in greater or lefs fluidity and volatility, by repeated diftillations, therefore thefe diffe- rences are leflened, and all oils are approximated to a com- mon ftate. Thefe experiments have not been profecuted fo far, astoena- ble us to determine the poffibility of reducing all oils to one and the fame ftate ; but every thing inclines us to believe that poffibility : and in this cafe we muft conclude, that oil in its greateft purity and fimplicity, and which might be called the oily principle, is effentially and identically the fame in all vegetable and animal matters ; and that the differences, al- though very numerous and confiderable, betwixt the feveral kinds of oils, proceed only from the extraneous matters combined with them, by the mixture of which their eflen- tial properties are more or Jefs altered or difguifed. We have further another very important confideration ~ upon this fubjet, to which we ought to attend, and which feems more unfolded, and difengaged Acids h I ave In genera] 5 produce very weakly or no : t fe in a large quantity Tor a € more thy rong affinity, Water and phlo when they the principles of Pies of the oi], wi they unj egree of oul, with a fo Y unite then to which jt han Senigration of the hy Proportionable to the Ple, and with bly upon oils, water; becaufe this n faturated, Prevents thejr 1 2 and with But Con itr sin pa vitriolic acid appacp Sond oil, occafions an eh tio apors, the fme]] [ h i powerfully a1] ¢ Han, confiderable ig at of volatile fulphu. By this Mixture, the » red, or blackith, ang the oil ig foo cheng : ner eff ng of oils, that when the ii id i vi O1L mixture becomes red-hot, and is inftantly inflamed, See INFLAMMATION of OILs. The a&ion of even the moft concentrated marine acid is very different from that of the vitriolic and nitrous acids upon oils ; it is much weaker, and we may even fay that marine acid does not form any union with oils. The difference of the effets of thefe three acids upon oils evidently proceeds from the difference of their affinities with the inflammable principle : for we may obferve a fimilar gra- dation in the action of thefe acids upon oils, and upon me- —tallic fubftances. As the feveral kinds of oils have their peculiar charaéters and properties, they alfo thew confiderable diverfity in the phenomena exhibited by mixture with acids. We fhall find {ome derails on this fubje& under the feveral articles of the different kinds of oils. We fhall only obferve here, in ‘general, that the vitriolic and nitrous acids are difpofed to unite very intimately with all oils that are very thin, volatile, and inflammable. But thefe qualities make them even clude the action of the acids when much concentrated; for during the rea&ion, they are almoft entirely, and fometimes in- ftantly, diflipated in vapors. The oils which are leaft thin and volatile, and which are difpofed to thicken fpontancoufly by the evaporation of their moft fubtle parts (which property they owe to a certain quantity of refinous or gummy matter contained in them), are capable of fuftaining all the action of acids, and there- fore are the fitteft to be inflamed by mixture with concen- trated nitrous acid. Laftly, all oils which have a certain degree of unctuofity and confiftence, which are not volatile, nor difpofed to thicken by evaporation, refift more the ation of acids. They are not altered, nor are half decompofed, like the preceding oils, by acids. They unite with them more flowly and difficultly, and can only be thickened by the united action of the vitriolic and nitrous acids. By being united with thefe acids, they receive the charaéter of an acid foap, or greafe, as we fhall fee in the article of thefe oils. The acids alfo are altered by combination with oils. We may fay in general, that acids are rendered weaker and milder by union with oils, and that this union approximates them to the charaCter of vegetable acids, or even entirely aflimi- lates them to thefe acids: fo that if it be true, as we have reafon to believe, that vegetables and animals are formed from minerals differently modified, the differences betwixt | mineral : acids of 1 be attributed se." CCtabI py iS OBI flefs td the oily privicip itia} fufficiently funy would ye Which quality of $ have not yet y as they defers 5 and on the 0 fcentrated that they oe decompoft ther. > they will they fenfibly ajter : parat it ilat; I with which Ad Wi We try, fori sc ve try, for inftan triolic acid frp his ce, to fe n . ’ 0 the Vie €€n combined jp In from thence 1 3 a certain qua. fonger yjtri. ituming retort : re Bre abundant than i pos diftilled 2 this exper; ument I tly nel : we evide mpofed, that the bins I acid j fulphureous, a oi nature o earns > 4nd SULPHUR, bo oy y of water mixed with th uh s 1S Cert So le of the oil, f J 3 Parc of the watery riper cof dh : : atery princj- the union i an by becoming ot approximated : ULPHUREQUS t contradys with a oil. Laff} i. t diflillation, beer, ciduous eo ie ¢ a large “Parated from the other ry par ticularly from ¢ confti ¥ O1L the vegetable acid obtained in the diftillation of oils without addition, does not appear in the prefent experiment, becaufe it is difguifed, or even decompofed, by the vitriolic acid. I do not know that mixtures of concentrated nitrous acid with oils have been diftilled ; but probably phenomena fimilar to thofe we have mentioned would happen, with thofe diffe- rences only which would be occafioned by the particular pro- perties of that acid. Of .all the experiments hitherto made on the combinations of mineral acid with inflammable matters, thofe concern- ing the mixtures of mineral acids with {pirit of wine feem to promife moft fuccefs for the tranfmutation of thefe acids into vegetable acids ; becaufe the mineral acids are very in- timately united with the principles of the fpirit of wine; becaufe thefe acids are neceffarily diluted with the water which is a conftituent part of the fpirit of wine, and which is in much larger quantity than in oils ; and laftly, becaufe the action of acids upon fpirit of wine is fuch, that it en- tirely approximates that fpirit to the nature of oil, altho’ the inflammable principle of fpirit of wine be not in an oily {tate,and although all vegetable acids do manifeftly contain an oil. Accordingly, if we would profecute this afiimilation of mineral acids to vegetable acids, the beft method feems to be by treating them with fpirit of wine. See SPIRIT of Wing, ETHER (VITRIOLIC, and NiTROUS). All oils diffolve fulphur, and form with it a compound, called balfam of ulphur. The connexion of phlogifton with vitriolic acid feems to be much weakened in the {ulphur by the intervention of oil ; for if balfam of fulphur be diftilled, the fulphur will be totally, or in great meafure decompoled, fince only the fame principles are obtained by this diftilla- tion as are obtained by diftilling the combination of the oil with vitriolic acid. Se¢ BALsAM of SULPHUR, and SULPHUR. Alkalis a& upon all oils, and combine with them to a certain degree, but more or lefs readily, according to the nature of the oil. In general, the lefs thin and volatile any o is, the more eafily foluble it is by alkalis ; and recipro- cally. From the combination of an alkali with an oil refults a compound more or lefs thick, called foap. ‘The oil which enters into the compofition of foap becomes eafily mifcible with water by means of the alkali, but ‘is not perfectly dif- folved in water ; for the folution of foap has always a white milky appearance ; which fhews that the oil of foap dif- folved in water isin a {tate fimilar to that of an emulfion. Thi + This proves a¢ the fame time, that he comb with alkalis is not intimate . | | 3 accordingly the qi] receives ng teration, or fcarcely any from the alkalis : ‘for i feparated b 1 it i be united wit tack moft fen; without heat, and from thjs ining matter, The action bly copper and ils are moft eafily as minjum, cerufs,’ an Preparations are myc divi greateft difloly; and leaft vola¢; in fmal] quant; but diminifh it, and giv much more read;] . Thefe of, called drying oils, from their rying quality. of lead js combined with oil, opake, and tenacious body Thefe combinatj ¢ €onvenient conf; Y form com that they Communicate ¢ unctuofity thay foap doc manner ; that the oil ¢ feparated from the leg means of acids anner as alkaline {oa Ps ma I thus {eparat ed is entire) Thefe com been exam; 5 neverthelefs, they prefent articulars, We now pfo- animal fubftances contain us, mild, and peg volatile But, in general, the off Wo very different ftates, which m each other, firft at of butter and fat, animal oi] js thick or ¢ This kind of ongealed, and owes this Quality to 3 confiderable ination of oils O1L : ith ity ip pd ly combined wi | . f acid intimate action of fire, of ponfilersiie gua: be unfolded but by the and which ¢ i me. 3 Ales d tralls in tim a rancidity it con by the ranc .. 0 form of butter or fat, . ich is in form of & 1 matters. "The oil of Sp, Wiis principles of aa aim] is not combined wit them, is fuperabun ifforent from that It is diftinct from of a nature t oul bftances. ' This fils vrhonitien, 2304 with the ie called oops oo lols. 1s combined Wit ih mn ils ealled pro: a animal oil, Niu = vegetable Big faline fembles perfectly wa re thefe, it LONER fie ily mattets is perl fat ails 5 and, acid, The acid o Sekar Hence bine th 2025, ee eof i mote intima to become ran tion moft diffi- they are dh io oh and are by fos " PUTTER, Wax, by fopestad a thin and volatile. ls are tly rendere T). ined in animals ar oy and O1Ls (Fae which are ly {permaceti, Theol of oe cxpreficd oil of yolks of eg found. is marrow, tix ture. i . is found, others of this which the oil of es almoft The fecond fata "The fubftance 0 bodies, as flefh, in Sa of Sr compofing anime’ > hair, So ntirely a tilages, bones, | hich does n rons, orally foluble in watery Snls ter being A elatinous, per : arency of water. il. which is one of t : ifturb the ‘(hes a large quantity of Seo JELLY. As this 0 tilled, furnifhe mpoled fubftance. atter before it has been parts of the decor ee gelatinous ma &l foJuble in water, does not gppear 1n this matter 1s perfe . Yes of jelly, and Is decompofed, and “oil is one of the princip means of the faline re doa pefoely mifcible with water sendy in a fate per- rendered perfeltly matter ; it is confequ don , : : 1 principles Ay has received no Sloss fo fedily fapans gelatinous matter. abfolutely mild, oy 2 for Wheén S . ears iling-water 3 ! the oil which it ine heat of Se teilation with fo alae as hy ei furnifh Akbis Shih have peguliat relly and anim ting tho e. ut seh heat ba ae others ws ne pure, volatile ells, as mu 9 ied. they then re thin, pe- rs heat be PP options of iWhieh ought to be Jkali, and an oil 5 t This is the oil w {mell firongly ran and volatile. nimal oil, It has Re of volatile ronfidorsd as fie trie . ble, and mixed with alkali, SL dif a» SOE Q “Yor. 1. a ———— Se ———— I — i § oil, although perfec] {ure to air; O11 alkali. This oil b , dif 11 becomes more an . } ation, as is ri in the fia thick as it rifes in vegetable oils xs effentially from fu o i that the former oil AS caufe of this difference To rom al] cle of acid but Foes not appear to furnifh a Teemsito be, : > DUt rather volatile alka); . hires rele parti. ) atter oils contain ich i diftill an acid, which js -unfolded and feparated b y “OTL | preps MAL) RECTIFIED or OIL hot nimal oj] defcribed in ] 7 and rendered more {Tufficient number of dered alm oft as white, th; { . thir . this flate ic js capable i 2] volatile nervous fyftem, and of ments lations, But this oil j i il is particy and convulfive affections,” It is give twelve drops, incor The animal oil defigned for Om above-mentioned th; . ! innefs, as Dj name it . Ls I h troublefomeoneran 1 1S then very dear from the tye ole from the finallnefs or requifite to give it that thi e long and nefs of the quantity obtained Boe, and Uh EC es y well Prepared, is very fufeeptible os and even its thi which proceeds from — of lofing its whitenefs, color. Ta as it toppers, and expofed as litt] : Although all anima] fubftancer Borel! equally fit for furnifhin,. |, of being rectified into a gdod oi D we onghs to > _purelt gelatinous fubft all fat § for the oil of far.” ‘other oils in diftillation dey Jeshese Or (ANIMAL), a ] mately. combined with it. i Tay ity from’ which it j i ke. Feber and therefore is not i me] be put, as »_10to very clean glafs bottles, with glafs s poflible to the air. contain this oil, they are diftillation, an oj] capable ippel. For this purpofe $0 als which contain the » which Recolor «rd io be » contains, as we hate ret, the arge portion of acid Sr chufe the parts of an; nearly fo nimal oil ; befides that ne of iy shea ed an | Qn acid, O1L acid, and the other an alkaline quality, and therefore their medicinal effeéts are probably different. Accordingly, as ‘the flefh,: bones, blood ‘of animals, contain always {ome oily {ubftance of the nature of fat or marrow, they ought not. to be chofen for the preparation of the oil of Dippel. Horns, and particularly thofe of ftags, which contain very pure gelatinous matter, are the animal fubftances from which the greateft quantity of this oil can be obtained in good con- dition. 2 "The moft important obfervations concerning the method of making the oil of Dippel are : Firft, to change the veflels each diftillation, or elfe to clean them perfectly; for a very {mall quantity of the thicker and lefs volatile part is fuffi- cient to fpoil a large quantity of that which is more refti- fied, In the fecond place, Vir. Beaumé has obferved, that this operation may be greatly abridged by taking care to re- ceive none but the moft volatile part in each diftillation, and to leave a large refiduum, whichis to be negleted, and only the more volatile part is to be further rectified. By this ‘method, we may obtain in three or four diftillations a con- fiderable quantity of fine oil of Dippel, which could not be obtained after 50 or 60 diftillations, without attending to this circumftance. (5b) OILS (SWEET) obtained from VEGETABLES by EXPRESSION. Vegetable matters, at leaft many of them, contain an oil in two different ftates, as animal ‘matters alfo do ; that is, in vegetables a certain quantity of oil is fuperabundant to their combination, does not enter into the compofiticn of their proximate principles, is diftinét, and is depofited as a referve in different parts of plants ; and alfo in vegetables another quantity of oil is combined, and js one of the conftituent parts of their proximate principles. Such are the faponaceous extractive {ubftance, acids, eflen- tial falts, mucilaginous matters. Of the former of thefe vegetable oils we treat in this article, This fuperabundant and uncombined oil, which may be obtained from certain vegetables, may be diftinguifhed into two kinds ; one of which is acrid, volatile, and odoriferous, and is called #/fen- sial oil; the other kind is mild, is not volatile with the heat of boiling water, and has fcarcely any fmell, Of this latter we fhall firfl treat. (5) M. Monnet fays, that by mixing acids with animal oil, their reification may be very much facilitated, Mifceil, Taar. Tom, IV, Q.2 Moft | O11 Mott grains and kernels are t fuperabundant oi], If thefe fub pounded, this oj] appears, and exfudes fro riturating them with water, the oil js of ah emulfion; and b tity of oil is fo hen the ftances be br grains and kernels from which oil is thus eg. cent and preferved from rancidity, the oi] oh mild tafte. It is a¢ fir a little € other parts of the but thefe ma s afte feparate in form o and the i] becomes clear, efe oils.are never very fluid and thin ry, they are confiderably un&uoys. The tile as to rife in diftillation with the h as we have already faid ; and when th o ftrong as to raj fiderable alteration, yet by diftillation the reumatic, eat of boiliny » are continual amed without a evaporate them. a ftrong fmell, are occafioned by produces: effects flowly and weakly. i ich is intimate] bined, with thefe oils, they are recent and ha more and more as they become old, jn it does by expofure to fire, his is the reafon come acrid in both cafes : red, the f: ac bifity in pirit of win they had not before) as they haye become more ave been more frequently diftilled. r. Macquer “has Thewn, in his Memoir concerning the Diffe of Oily Subftan rence of Solubiljts ces in Spirit of Wj that this entirely de- pends on the ftate of the acid of th ances ; that they ore foluble as their acid is more copious and 5 and reciprocally, We fhaj] find fome parti- culars upon this fubjedt at the article EsseNtiaL O11, Of uifed any m them. RB reduced into the flage Y expreffing them, very large quan. rced out of them, turbid, by grain or kernel ; f fedinent, 5 on the conti Y are not fo volze g water, €Y are expofed to a heat. fe them ; they then fuffer a cop. mentation, which rey but much more - i com- not thew jtfeif when ve not been alte difengages jtfelf ame manner as why they for the fame reafon alfo, they quire fo much greater {olu i Bf 2 1 is, and for forming 39 0% ith fixed alkalis, ang ine metallic proper for Ue Ng ‘alfo for diffolving metallic ood foap (Jee r , and whic Bo, ¢ fuperabundant oils in vegerables, refemble “All the fwset op extradted ely b catio : i re cap al prope the degree 1 each other by oe from each other J ¥ Some of thelg they differ con oC thefe and other proper difpofed to become which they poss nuts, hempfeed, are a Po they are capa~ EAnid fo thicken, an tory very quickly; hey congeal- anci UN e of co ixed’with vitrioli ble of refiting a Fe ee muds when rs ‘ed ; they form 1% jg are eafily inflame d Y Other oils, as and nitrous acl Te. Rouelle has opfervel: &c. become pitrous ged, lives, {weet 2m 5 they cannot be oii ofe of ben, id and thick ; f cold ; they much wre a with a very igh ee and nitrous dried ; they bine wit hich rather on lefs pels 4 acids Coons, , oa hi acids ; they form s Mr. Beaume ncurrence Te ily, cannot be inflamed, but by the concurrence of and, laftly, “1 itrous acids highly con fe& refemblance to the vitriolic an 2s to confiftence, a per nd as they exhibjt latter oils have, pill ( Jee thefe guords), % deferve to be dif- butter, fat, an henomena, they ju Jor denomination of Ce hed from al others by the particu | tinguifhed fro : ay range fome con- at oils. latter oils, we may tables ; fuch / In the clafs ¢ ic hd obtained Fr I) perhaps crete, oily, an Cacas the green wax of vamined. We may re the oes ae not fufictutly Der of fweet os many other: the gre tile, fevera afily Depeeives reifion, and which are » As of one or obtained by a or lefs partake of t juft mentioned. : of them muft more cipal kinds we have called effentials other of the swe NTI AL). Thofe llsgig of Tih OILS (ES he {mell of the vegeta olatile to which pus ody ms thele oifg are fsinly jm of they are obtained. f boiling water 3 fe oils. _ They rife with the Bo 0 ecific marks of dufes mentioned volatility is 1 others and particularly fr £ volatility, which fides from ding article, by this degree 0 in the prece is peculiar to them. Q3 | 01°" We have reafon fo elieve, that the greateft part of (ha Eliential oil, which certain vegetables Ccntain, jg of combination 18 ina flage » and makes part of fome of their proximate principles, We are, however, Certain, that many vegeta- €s contain a fuperabundane eflential oil, Uncombined, apnq depofited , S$ a referve ip Particular cells - fuch is the oj which refides In the rinds of oranges, S, citrons, in 5 ds ich oil js fp Copious, fuch proba. parts of plan 1, is found in the calix of rofes, but in too fmal] quantity to be obtained by expreflion alone. » as all eflentia] oj] are capable of rifig of boiling water ; and as thi de- €at cannot occafion any fenfible alteration upon {ily be feen b Y comparing the eflential of] of » Obtained by expreflion alone, with the cted by a we] managed dif. therefore, may be obtajin- oyed in chemiftry ang ip . \ the arts, Phe molt ufual and beft method of obtain; oil of 3 vegetable by diftillation, i prime of age, when its f thofe mell js ge to put them in the cucur 2 n which the fme]] Chiefly refides 3 bit of an alembic without water- 5 to add as mych water as is fufficie plants from toych ic bottom of ¢ 1e alembic ; a gree of heat which jg Proper to make the n this diftillation, the water fmell of the > and it carries tidl oi], this oil. is fo water which rifes in diftillation, that it renders milky ; the reft of the oi] floats upon the furface according to jts ‘he diftillag the water becomes clear; to time, be put into the always kept, moift with it, feveral p cular pr T parts of the plant ath rifes im pregna along with it intimately mi ted with the all its effen. xed with the it turbid and of the water, fpecific gravity, be continued, ti] plant'may be reafon of the anation of the parti~ e thall fee the in the expl ential oils e oils ha cady faid, by arts of this procefs operties of ef] ot only thef we have aly ve all ftrong, aromatic fmell, as t they have alfp fingular, and even an 01L" . hey differ from Juftic tafte 3 in which pn us and dif- RY and Ca This tafte proceeds oe ay \ ] the ye ols with which they oe RD flential Bile, ap engage of ce of this difengage upon the corks of | i: of The prefenc reflion they make ) are always ftaine s from theimp t. Thefe corks s they are by . Fe which they are * little wrote, 153 i reddens blue a yellow COT fides, the hk Nes with which. they are nitrous acid. ‘1s convert alkalis, . 3 ; and the ol It. 5 tial oils in pl rated, into pia dg the folubility of of on this men- This acid is te are not all equally 0 equal quantity of fpirit of wine. = > do not all contain oe does not adhere ftruum, becaufe ne almoft difengaged, : by repeated diftil- acid. As thisacl ils, they lofe mucho o {pirit of wine is ftrongly in {hala ous their Iplubility 1 Age oils, which, lations, and t rations ; WNEreas nd are therefore leflned by thefe operat difengaged 26 hie. in that men- when recent, con f wine, become 10 their latent acid, infoluble in fpitol Wit difengages the folubility ftruum by dititlagia bined with them ; s the diftillation, that was intimate Ye repeating many time woted in the pre- may be On in the Memoir q ; ha i as Mr. Macquer .. by evaporation, he ding article. fubject to lofe, by ‘fic fmell o A elfen thin part, in which ined, refdes 5 by moft volatile om which they "i TN the confiftence the vegetable, become thick, an S. : which lofs they entine, or even of Wig properly {peaking, and {mell of turp ftate, they are not ile with the heat o When 2 they are no longer volatile » eflential oils, as t not yet entirely bo We femtial oils, altered by oiled with the hast When eflent eculiar fmell, are in diftillation, whic deprived of ther os part of them ue frefhly diftilled. As of boiling, water, rties of eflential oil operation, it is fre- has all the Dl is renewed by it egin to be altered this portion 0 i n eflential oils, whic! led the rectification. quently practife 0 ond diftillation is ca fter rectification, by age; and i find in the cucurbit, o longer capable of of effential oils. ‘on of the oil, which 1s n re oily refidu- the refinous port heat of boiling io ine with a ftronger being raifed by the be attenuated by difti Hels of effential oils a en al the volatility and hint matters, by dif- heat, and even : as alfo to all other oily tillations i to 1t, may be given Qi ’ fr om their volatile from the SBiritus vesor of the hey were obtain ; {ince they have volatility which diftinguith * ¢hem, FL erve this principle, ang lofe all “thefe Pros Pertics when 4 evaporates Thefe fads alfo fhe ty of applyi very Ys the degree of heat requifite for the raifing of thefe diftillation ; for We may eafily per: ive, that as the h lefs than W the neceff; has Joft at, no effentia] oi be obtained, or only a much Jef quantity of je, {piritus reQer jg entirely foluble jn water, theres oyed in this dilating of eflential oj]g rge porti is fpirit, and eyen ‘becomes aturated with je, this water jg much ime mell of ‘the plant; bug the oil by this ity than it otherwife would be, infer, firft, that ne more water thap is 5 and, fecondly, that the be em ployed A Pregnated with the |; means is iin Jefs quant ence we may tyof it is always. feparated ollefted, Eflential oils are in ge inflammable of al i caufe they are the. ile, and moft eafily re. ducible inte vapors. €Y unite more eafily with acids than the feet oilg which are not volatile. With thefe acids they form refinoys compounds, inflamed, according tothe nature tion of the acid e or are and degree of Concentra« mployed, | They We may conclu O1L : n the faveet oils : re difficultly omiiigble shen 4 which they They are RR s with fired 4 ope of STARKEY. _ which are no lar kind of foap. See be obferved betwixt form a particu able differences may in general, they are Some Sontersy oils. Although, life water, fore of feveral eff ith the heat of or quantity by a oI capable WE ubtsings in Bix om rin dh hem, howev & ; and this is effe h are incapal the water felts and by means of whic oo 3} upon Ol > ’ heat. “ an t A bleof receiving oki, of thefe oie de lof thy of this ’ The fpecific 8 ordingly they float upon fo heavy as to fink of water, and oe hele oils, however, “ie obtained from the liquid, Some of bod are the effential oils loves. cinnamon, in water ; of s of hot CQUnLRES, As thefe heavy oils a aromatic vegetables the diftillation of oody, and compact faflafras, wc. hiefly ufeful. Dry, SF their effential oils, ftronger heat 1s iy; to the diftillation of tion during foms matters, iftanse of divifion and macera require the atl . . aries much ; fome S. flential oils vai itron, being days. confiftence SS ementine, fefufas, wpe: rofes, have Shem, ss thote RS, like Gals > even congealed, unlefs yery thin § h confiftence, an turally much coniiiient of heat. ial oils pro= they fuftain acer tain Jogres confiftence of Herts as all the ! Although the wel ght {tate of Shelr acid, 3 two. properties ed roba y twixt them, ye oils are, at other differences Sets each other ; for fome ¢ gtisers are feem to be indepen thin and very pen which is very the fame time, hick. The oil of faffa ntrary, the oil .of very light and ” than water; on She Ames equal to that uid, i, fe oniiftence of which is {ometimes eq anifeed, the floats upon water. d from different we- of congelation, f effential oil obtained fre The quantity o r g g b cand refinous trees, d moft balfamic an as rofes, for frig, Lule et of oil. From rit h obtainable; funiihsg dy a fenfible i much pow inftance, Ithough they :C flential oi k and, po have ouch {mell, furnith “tuberofes, and jal~ yedior, 55 f this number are lillies, tuberol diftillation : of t oy E flential pine. | allayin as cepha] attections ; the ening, All d and {tomachje Waters, In fome cafes rengtheners tendinoyg an withey fo as n form of pill a Property o of ing its irregy 106, and ant > eflent; > and to gy] Parts, to ref], occafion pai al oils to form zp ole ofacharum, or S. mable, thin, apg volatile, haye in g upon the nervous ve Cv 4} ifpafmod Y are alfo fim, Tugs which are » Which ulant, fudorific, alexi Pharmic, are emplos ployed €xternally a4 lay painfy] 1, palms of nervous ang € and diffipate | t any fenfible f hen eflential oj1c 'S are applied e they are Cauftic thae they my rednefs, frequ » and €Xcoriatjg velicatory, would excite pain, tous erupting adu terations, e Tention wha 1s moft ject. Effentia] oils may be oil, with {pirit of wine eflentia) oil. The P gentle heat | eave no greafinefs nor trap Mixture may allo pe difcoy O - Xternally jp thefe cafes, hot be applied alone, a5 they ently inflammation, eryfine- ity of fat, » With which m {carce and and are therefore 00Kks of che orof difcovering thefe fummary lanner ‘known on th Is fub- h any flavorlefs fat Common and chea properti €s of thefe fub- at oils are neither ial oil, ¢o be ex- aporated with , h fat oj] O1L 2, tirely ich it will be en / y il with fpirit of wine, by a it has been wale effential ir in phre from fe 3 l his will remain undif- . 1 C1 01 » diffolved if 1t b latter; kind o off ia with this ine. . flential oil m y pe in fpirit of Fi ; init of wine YO remedistely ac- "The infin addition of a W a fpirit of wine Juits difcovere y nce: becaufe the oil much di- Bek a milky appearin water, and Jiavey does not hap 1 Co i n . bv agita vided and oP {flential oil has indeed, yag . hen the e {ential oil may, nd may give a pen w ne. Pure el] 11 globules, a lok ils irit of win . to {mall g uickly four water, be frit but “thefe globules a Galt, whitenefs to Sew or at the bottom its . the furt: > itv. >ie Tre ie ftdifficult- again on their fpecific gravity. NG a of thefe corditia tion bY incipal p “1 oils are ly,adultera the princip tial oils 1 de becauie Neverchelef, as ellen fraud may oils are COO ated with oil of MR with he ol ulte . it of papg . il. whic commonly ed b foaking a bit 0 rating the oil, wh . : ickl evapo 1 of turpentine. be difcovere Tr and by quickly {trong {mell of turp Under to be tt the Viren or PEYREUMATIC )- Ur 1 . y YRE d anima will leave Pe TID, EMP ils of veoetable an that OILS (FE hend all the oi 2 {uperior to he btained by diftillation with ave a difsgreeable matters obtained Y eenufe thefe oils oo “boiling water ; tic fmell. umatic oils a iy or ve fee, that be ory different om From this : fs; that they may mmon, but that the diftinét clafs ave nothing in co animal matter rh ce, and Hy chen any vegetable of an of boiling ' all half-burnt; of heat {uperi 'of whatever kin is cxpofed th : SE hich they tare Bpaiky oy Be ter, all the oils, diftillation ; ther of their pe- they may be, pafs mel, and in many a diftilled con- fire, in their color, Befides, if the ipo together when culiar Properies. of oils, they are “Lf for example, a Ver tains feveral ered SRY roimane. ontains an oil Hens id yar 4 ne vhich c te, the fe they are rel be diftilled, which a refinous ftate, hefe etable matter Ifo an oil in ixture of thef gel not volatile, od aw will be only a my animal mat- empyrenmatic bi rN The fame may oe animal oil, and to two oils Bf the oil properly calle oh i oil which they contain, the adipot Ng ® 1 o ger) propre” 9 genera] pr os Operties, thea, hn be efablifhed be . - Lk ley all var as IC ‘ oils of . Y accordin Pyreumatic oil now Agi they are or p oportion of oils COREL | k Properties of ap Pas been obtained, ans ed i8 the fubflancy. fie, Kinds an helt 0ls from the degyer OF0E Changes fuffuseq py ACh it ic. Wethay SL heat requifie gq. pe, 2h of € acrid, bf fender them . 0 De Common proper, : mi as fo called, Y are accor Nevertheless, He time of Je OIL 0 antimony” and (LIMONYY, By th; ate called. ome other folyti, Y this name the fame mane, arfenic apd of corr wallad Mercury ; LC "hen w . galled 2yr4,4 min In vitriolic acid 3 rater is a POItion of mer. 274 the: ac form ¢} mercur . s d apercury. Thy 4 diffolyed, which ; iluted till : 's Which retains 2 . 18 Proper] . i crptallzable, may be our tained O1L tained by evaporating the water which keeps it diffolved. When expofed to a moift air, it deliquiates into a liquor which Lemeri calls oil of mércury. See TurpiTH MINERAL, Lemeri alfo gives the name of oil of mereury 0 2 folution of corrofive fublimate in fpirit of wise. . OIL of LEAD. Thisis 2a folution of falt of lead in the effential oil of turpentine. This falt is to be put intoa matrafs, and upon it oil of turpentine is to be poured, till it covers the falt with a thicknefs of fome fingers; and the whole is to be digefted during ten or twelve hours. The liquor, fays Lemeri, acquires a red color. The author di= rells that the folution fhould be concentrated, by diftilling from it a part of the oil of turpetitine; and he recommends it for its utility in cleanfing and cicatrifing ulcers, parti- cularly thofe which are putrid. This preparation, which is certainly a powerful antifeptic, mut be very proper for thefe purpofes. Among the oils improperly fo called, this is one of thofe to which the name of oil has been with leaft impropriety given ; for the bafis of it is actually oil, and that oil really keeps the lead in folution. Lemeri affirms, that we may thus entirely diffolve a given quantity of falt of lead, by employing 2 fufficient quantity of oil of turpentine. This - preparation, which has only been made for medicinal pur- pofes, is interefting alfo in chemiftry, and deferves a parti- cular examination. OIL of SULPHUR. Some chemifts have given this name to the concentrated acid of fulphur. Se SUL- PHUR. OIL of TARTAR bh DELIQUIUM. This. name very frequently is given to fixed alkaline falt refolved into a liquor by the moifture of the air, or even to 2 {olution of that falt in water. This name is unfuitable, not onl: as this liquor is not’ of the nature of oil, but alfo becaufe a true oil of tartar is obtained by diftillation of tartar. This liquor ought to be called alkali of tartar, or liquid vegetable alkali. See ALKALI (Fixep VEGETABLE),' and ‘TARTAR. O1L of VENUS. Lemeri gives this name to the falt formed by the union of copper with the nitrous acid, when it is refolved into a liquor by the moifture of the air. It is a cauftic and efcharotic, like all other fimilar combinations of metallic matters with any acids to which the name of oil was formerly given. "An empyrical phyfician has rendered this name of oil of Venus famous in thef¢ latter times, by 4 having dittillation. May be obra From ned iri obtained by water) ute Wiis (/) O Newmay, Ties by PAL isan almog pellucid reflexi Xion and refradtion 3 ’ or 8g . 1h RCoe! ’ quires a bright yellow NYX is ap = Veins 1 go Ss paralle] tg (7) Opry In curve lines, 'PIUM js I Rl 2lmof totally foluble ; Aer, Water, ang eon? Min a " Jags Portion of (3; Ine acidy] ous at its pecul; Peculiar properties de- pend, Mmon] cid. So ORES OPOPONAX. (0) ORANGE. (p) | ORES. Ores are natural compounds, containing me tals allayed with different fubftances.. Excepting gold, and a very {mall quantity of each of the other metals found in fome places fo pureas to poflefs all their chara&eriftic properties, nature exhibits to us metals and femi-metals differently allayed, not only with each other, but alfo with feveral heterogeneous {fubftances, which fo alter and difguife their qualities, that in this {tate they can- pend, we do not well know. When opium is diffolved in water, a fat, frothy, refinous fubftance rifes to the furface, which is fo ftrong and ative, that a few grains of it are fufficient to kill dog who could bear a whole dram of opium. From a pound of opium two or three drams only of this fubftance may be colleted ; but the opium contains more of it, which remains combined with the reft of the juice. The narcotic matter of the opium appears to be diffufed through all its fubftance, but more efpecially to refide in the fine volatile parts; which parts are capable of being highly concentrated by art. Neuman (from whom the above 1s extralted) fays, that he knows a preparation of opium, by which a whole chamber full of men may be prefently ftupified, deprived of their fenfes, and even of their lives, without {wallowing a fingle grain. He thinks that it operates nearly in the {fame manner as the vapor of burning charcoal, or as the exhalations of ferment- ing liquors. The fame author propofes to render opium more mild and innocent, by diflolving it in water, and fermenting the folution. Dr. Lewis obferves, that diminifhing the dofe of opium is a more certain method of diminifhing its effets. He alfo fays, that alkaline falts diminifh the foporific power of opium, and that acids almoft totally deftroy it. (¢) OrorPoNaXx is 2 gum-refin, of an ounce of which two drams and two fcruples are f{oluble by fpirit of wine, and three drams two fcruples are foluble by water. Both water and fpirit, by diftillation with opoponax, acquire its flavor; but no oil is there- by feparated. Neuman. (p) Orange. The flowers of orange trees afford, by dif- tillation, a very fragrant eflential oil. From therind of the fruit an eflential oil may be obtained by expreflion. The juice of the fruit contains an effential acid falt, mixed with much mucilage. This falt may be obtained in cryftals, by diluting the juice, cla- rifying it with whites of eggs, and evaporation. The juice, not depurated from its mucilage, is apt to become mouldy ; but by the above-mentioned method of depuration, a faline extract may be made, capable of being preferved, and pofleffed of the fame medicinal qualities as the juice, which is {aid to be very power=- ful in the {curvy. not When they are 2. of tHE Purpofes f The { aye fufficient] or which they d a the he fubfance found abr: #e proper the Ble und naturaly wom: } feparately, bt grate : elphur Wa ih metals, ; oh thefe fab ly conj inely M fenie, fometimes ar arfenic, or py 9 “i called meth “als, Combine led iain fr is and he nocldes the fojnh : © ele matters ape riétly combin Phur and 4 I > are eK ed : rfenic wi pe Htimately combined the miners] Rate, yy hich metals ape P tures, and more with earthy fubft €y are alfy ret usd to metallifagion divided, i; * of di re nation ar » and is conver TC of this e, Jee ly proceeds Phlogif vertible ing Which pe a, 20d deftro 1 we hall mention uced into metals 1S 1s an ? are com ordi metal] a Mary earth, quently poffeffeq Whi of Propétly called orgy, The ORES "The other ftone is lefs hard, does not ftrike fire with fieel, and is fometimes milky like quartz; fometimes tranfparent and diverfely colored, confifting of rhomboidal cryftals, which are compofed of plates and faces. This ftone becomes more foft and friable by being expofed to fire, It is called fpar. Spar is more like to gypleous ftones than any other, but it differs from gypfeous ftones in poflefling a much greater denfity. Some ipars are fo heavy, that they exceed in this refpet all other ftones. See SPAR. Thefe earthy and ftoney fubitances ought to bewell diftin- guifhed from the earth intimately mixed with the ore, as is mentioned above ; this latter earth conftituting part of the ore, whereas the others are only accidental, and externally adherent. ‘They form the matrix of the ore. Mines have generally the form of veins, or of congealed currents, which have different dire&ions, and which are die {tributed in branches. The mines take different appella- tions according to the direction of their veins. The deep mines are thofe which defcend from the furface of the earth, either vertically, or more or lefs obliquely to- wards its center. Thofe which are extended horizontally are called dilated mines, becaufe they frequently are confiderably broad. Some mines compofe mafles more or lefs extenfive, and almoft equally long, broad; and thick. Thefe latter are called accumulated mines. Some authors have faid, that the veins of mines are always dire@ed from eaft to weit, from north to fouth, or in the intermediate directions, according to the nature of the metals, But this opinion is not well fupported by falls; for we are certain, that veins of every metal run in every direction. The dire@ion of mines is determined by their defcent, like that of rivers, and by help of a mariner’s compals. From feveral figns we may know that a field or 2 mountain contains a mine, particularly when the mine is near the fur- face of the earth. For, from grounds filled ‘with minerals, fulphureous and metallic vapors rife, which are fometimes fo confiderable as to affect the fenfes, but which moft fre- quently only thew themfelves by the effects which they pro- duce on plants, which they render weakly, and difcolored. Frequently even, mineralogifts fay, thefc places are entirely barren, and no vegetables grow there, although the ground feems to be of a good quality, and fit for vegetation. The fources of mineral waters ; the nature of the flones upon the ground being that of quartz or fpar; bits of mine- Vou. Il. R rals filvery becaufe 60 pounds of | the largeft qua without attendin In this manner, an ore of lead, and not an ore feems to be, to Ore an ore of lsad containing filer, as is very frequently done. particularly attended to th; call an ore, the largeit quantity, and to cal] j ORE § rals lying on the ground ; are fo many proofs of the pre. fence of mines. But we muft not altogether depend on thefe figns ; notwithftanding ¢ em, we often find no mines, or very poor ones, when we dig the ground. The digging of the ground is then the only certain me.- thod of determining the exiftence of 3 mine, and of what kind itis; for the wand of divination, by which many pre- tend that mines and their quality may pe difcovered, which owes its reputation to credulity and igno- Metallic minerals are divided into two clafles, includes al] thofe, in which the quantity of meta] exceeds the quantity of fulphur, arfenic, and unmetallic earth; of rom which meta] may be advantageoufly extraéted. Thefe minerals are particularly called yes, . In the fecond.clafs are placed all miners] which contain, More fulphur, arfenic, and unmetallic earth than meta] ; and thefe in general are called Dyrites, Pyrites and ores are of the fame Nature, and are often both found in the fame places. But as the Proportion of the prin- ciples of thefe compounds is diff; >» thei differ. We thal] explain the properties of article PYR1TEs, and the properties of article. : Ores may be confid ufefu] Pyrites under the ores in this prefent ered in two ways ; firft, as contain; and valuable fubftances, and they then receive their luable metal which is obtained from for inftance, as filyer is much more valuable which contains z mark of > Or more, is called an sre 4 the mark of filver js more valuable than the + This manner of denominating ores is ‘chiefly ufed by the miners. In the fecond place, we may ntity of which , ineral, a quinta] of filver, and fix ty pounds of lead chiefly attend to the metal is contained in a mineral, g to its value, and affix jes name to the ore. the ore juft now mentioned would be called of fiver. But t he beft method call fuch an r. Cramer, a profound and judicious chemift, who has s fubject, thinks that we ought to proper ore of that metal which it contains jn t the improper org of 31] the other metals ORES iftinguithing ores is it may contain. This method of Uglies 2 else of the beft and moft al Sedat admis oo sas Lo HA of the principal kin ma Failic fubftance. (¢) ORES iftry, we 5 Sul i t of chemiftry, w A . tt important par rticular Hurgy is the mo ; a more, partic ; (¢ ), As a frch of rhe Hiftory of EF together nih a ope tha is containe ing metals from i res than 1 ds of extrafting enumeration of 0 ved methods © ufalure, ‘ oft appro merce and man relation of the m f¢flay, or of, comm 1] treat of rpofes © J» fent Note, we fhall ores; for the pu e. In the prefen ile. Tt thertext, may not be wasceeptabl general : Under the setidjes | fubjoin a mines, rn of the ores of the feveral ly e and alfo the me- which trea : hich are there om ’ ities and ion of thofe which 2 difcover the quanti enumeration of 1 ores to diico ‘le SMELTING the fevera der the article SME thods of eflaying nts: Laftly, under the ; hods of . . », oo. £ met 0 qualities of Tp fome additions concernipg the purpofes of of ORES, We ha) from large quantities of ores fo extrating meta commerce and manufacture. s. Concerning ORES and MINE in a calcined or rather llic fubftances in-a ca sth other ORES sonia, 7. 9 OF thefe fubftances a with o ealeiform AT they are faid A mer “ are metallic {ub- matters, ic fubftances, or calc; "of a calx, or me- Calcined metallic fubftz and in the ftate of a 2 ic ftances Jepeived 2 Eg are all ferruginous ochres, whl h tallic earth. Se tT +o {ube are calxes of iron. e; 1. Simple, containingonly one Zaielie po Mineralifed “Compound, containing two Or more : ftance: or, 2. kinds may Rances. fimple,. and alfo of the compound ores, for Of the hu 2 ; ifed by fulphur. be ie ng of metallic {ubftances Paani by oily Such ie lend recalled gana; oe mineralifod by ar/enic. uch 1 : allic fubfta : fifting of metallic {ubit {enic. Such athe edit pits EO pnereiihd by fpr . C ini ver, re nfl of Bd Sfilver-ore, containing 1 and Oy arjenic. . ifed by /aline ‘arfenic, and PAE metallic fubftances nl. the 4 Oig Soh aes 8 native witriols. ag opinion, matters. ] u ore, which, according to Mr, vine acid, To this guns flat an “or filver combined with alifed by an alkaline fub- is a luna cornea, rred the filer mineralijed by a d. clafs alfo YY oe Co pretends to ig Sion the Dic- fiance, whic d after him Cramer, and t i d ores, befides the Hsieks miley pretend that In mineralile ’ 2bove- tionary of ’ R 2 ORE 3 D. In taking the word srs in the fenfe ores of gold exift ; for as this meta] He Loo eid cannot ORES of GOL abovementioned, no ifing fubflances, € earth, But Wallerius hs cannot be’ thewn, and metallic earths, and even excepting ‘tho {e of lead, bify tinguifhed the feveral how they are lodged, muth, ‘and: njicke]. aving thus defined and'di general clafles Of ores, we proceed to thew and where they Sound in varioys places. 1, They ivers, lakes ang feas, and flexures of thefe : Such are tha auriferous and fer- ruginous fands, grains of native gold, ochres, and fragments of ores wathed from mines, ‘ i II. They are found Zp; waters containj ved in aiatey Such are the vitriolic ng iron, copper, or zine, ol L They are found Jnany ochres ; metaife “pon the furface of the earth. Such are rous ftones, lands, and clays ; and lumps of ores, Mr Gmelin fays, thay in ‘the northern parts of Afia, ores are almoft always found .upon of near the furface of the round, h Iv, They are found under the furfuce of the quantity of thefe collected in one Place is'conf; a mine, Subterranean metals. and ores are differen ferent places: I. Some are infixed in fones ang earths, diverfely colored, 2. Some are equably and 4; of earths and poy Properties. ‘Such are ¢h {ands, clays, cryftals, flints, gems, and fluors, which are colored. 3 ‘Some form Srata in mountains, Such gre the flates cop. taining Pyrites, copper-cre, lead-ore, filver-ore, or blend. Thefe lie in the fame direction as the ftrata of ftones betwixt which they are placed’; byt they differ from the ord; ftratain this circum- ance, that the thicknefs of different parts of the fame metallife- rous firatum is often VETy various; whereas the thicknefs of the floney firata js known to form, be generally very yp; 4 Fragments of ores are frequently found accumulated in cep. tain fubterranean cavities, in filures of mountains, of interpofed betwixt the ftrata of the earth. oofe, unconneéted, frequently involved in clay, aud not accreted to the contiguous Tocks or firata immed; tion of fpar or of ately quarz, earth, When the derable, itis called tly difpofed in dif. forming nodules of Spots Sformly diifed thro ¢5, 10 which they gf b the fub fiance €Y give color, dep 1ty, and other € greatefl part of thofe earths, ftones, > nor by interven Or WE ur, it is never "aii * Cue h falphur, 1t1 ) | vith arfenic, norwit -‘as the other a a in thefe: fubftances, as found directly metals Tin and iron mines are: he ores found in Nr x he doiey as the . {cribed. ) in the fton ants of the iad lis duty ny bon londy IONS lated weins, freq Large entire rele aie improperly i) Y depth, is not ountains. ively to their brea ftrata of m 1 h relatively . engt : nfifting aufe their ; ntains CO bec ble. ioned of entire mou A Auris confidera inftances are mzaes bere in Smoland ; es ae 6. Some Ini ountain Laberg ra in Lapland, cfg’ Sul tt and Le perches broad. tains. 0 hes long, a the ' mountain h is 1400 perc of which 1 iron-ore. d in oblong former tains confift of iro d lores are foun rata Thefe moun d chiefly, metals and lo h lie in the ftoney Oe muffs called weins, whic i tra&ts, forming at. ies; fome being flraig > compofing mounta: f veins greatly varie be oftin ¢ the horizon s The dictum of Their pofition alfore Be horizontal, an and others curved. being perpendicular, declivity. 1 : . me " S o - very various ; pe intermediate ar antity of Rusty fhe ng o ity, and the q ious. Min the reft bei & e nality, very variol . The ARIE of veins, Bre pu Lcprefiive of or ther circun i f veins by n endicular 3 bori- many othe al kinds 0 d . perpen i iftinguith the feveral | {aid to be deep 5 perpera oon; even- diftinguith A veins are laid or 3 morning y n0%s £€C differences, Thus veibs £7 3 ion towards that Po zontal, oF hanging, by which their direct thefe divifions of the ) d night veins, {un is at any ing, an 's, where the fu led 3 ais, wi . . called 1ts of the comp . ified. . 7e a vein 1s ca natural day, 1s fignihec or ftone lying above its floor. I The fram, atum under the vein thicker than others. sma’ roof : and the fray s are confiderably thi and Reatimesihel Some parts of ten ch out from large Ey they iffued. Thele veins frequently branch trunk from which art, have been ob- branches return fate many imaller veins dep . Velts, from wie lly rich. dual diminution, as d to be generally : ; 1. By a gra incumbent ferve inated varioufly ; 1. t foft, by fuperi dent Veins are termin refled, while ye! feveral {maller veins: or by fpluing and 8 gether with ther proper ioht : or ’ « t 0 . . £ veins an oy fra are So a anink or, 2. J. v lie. by new = : 1€ . - I rr cone by hs bing oid bn en " on . ca 10 ; ry ~ he Or » 1 e WwW trata 1s occa 3 »étion of th ~ uentiy + . tranfverfely to the rep . which fiflures graf "e T hefe perpendi- ne re he ’ e empty. | re or de- filfures through ¢ r with water, or ar : ¢ y {ome rupture or g¢ alluvial matters, ro have been Gealionsg V h e vein pafles, y cular fifires feem fratum through w de refled, or Iereoved rangemens of kag it has been raifed or dep afide bog r art oO 1 R ~ which one p 3 aid j : : fe from the other, rally Broken ai id abr 7 x analogous pares of fod is often rec Principal of the oppo overed modes of thes doer the art of mine, oC. OF the now where to Wher e the by Js only Jeranged firagum difcovering thi that they may foal” ' learc the fe feveral ki ife ; Inds o tes, b €rous miner are generally i uors, {pars, quar > blends, guhrs, vitri als, as, the n y imbedded Juartz, horn-blend. ; itriols ; the tions 2 matrix of the or inveloped, and ¢o Rrwhich the ores 0 . ore, . . : thefe metalliferoys | a “pplied ‘ : he ich therefore : : oney {ubft 5 cryftalliza. g the the rock op quently to z both thefs ent ki res t but nds of adhefion 0 0 the rock ; ang ore fre fequently betwixe oar In the fame y Rng - Cr . ae 3 ein : ult of fone or of x and + at differ , NC matrix > various kinds better adapte or 1 ores of particular metas 81Ve reception to all to copp er and filv. To OPP er, an : ashes to Teed, i; d never to tin’; cal but flates chiefly rs, 0 led, fr and Erb carcous and {parry guentsy in {ome kj hy eb r oe rompounded ftones lerous : ¢4/, ama accareous floppy « rs alert); Jeltfpar {ner Ferrers ometimes jaf; iv Or falty Rones = and J W indur articulis { De ata particulis {guamofs Cron pel gypleous or in f i Y contain metallic een obferved of ores of fi me kinds of € reception tq a : ore quartz, fpar, f] ores and metals | fone fe n ] Ore ic leem iy Ie, or to the uors, and horn 1 Tat Tole fre ‘x mm a lowing ple (cos fiffilis are. 1ve fcintillans) ; hiefly micas 1 0 i I d 7 gras, ’ t el granite, 01 In por | g 1 . in the : rata th 1 A vein ven O RES rally combined with fulphur and arfenic, fo fmall 2 quant’ty of it only is found in thefe dts, that they {carcely even de- {ferve the name of improper ores of gold. ; Hence A.véin fometimes pafles from one firatum into the inferior contiguous ftratum. Sometimes even the veins of one firatum do {o correfpond with thofe of an inferior firatum, the contiguity of which with the former is interrupted by a-mafs of different matter through which the veinsdo not pafs, that they {eem originally to have been continued from one ftratum to the other. Thus in the mines of Derbyfhire, where the veins lie in ftrata of limeftone, the contiguity of which ftrata with each other is interrupted in fome places by a blue marle or clay, and in other places by a compound fone called tead/flone; the veins of one ftratum fre- quently correfpond with the veins of the inferior ftratum of lime- fione, but are never continued through the interpofed clay or toadftone. But we muft obferve, that thefe interpofed mafles, the blue marle, clay, and toadftone, have not the uniform thick- nefs obfervable in regular ftrata, but are (efpecially the toad- ftone) in fome places a few feet in depth, and in others fome hundreds of yards. The above difpofition feems to indicate, that thefe feveral ftrata of limeftone have been originally contiguous ; that the veins now disjoined have been once continued ; that thefe firata of limeftone have been afterwards feparated by fome violent caufe, probably by the fame earthquakes which have in a fingu- lar manner ‘fhattered the ftrata of this mountainous country; that the interftices thus formed between the feparated ftrata have been filled with {uch matters as the waters could infinuate, pro- bably with the mixed comminuted ruins of fhattered ftrata ; or, with the lava of neighbouring volcanos, of which many veftiges remain. To the above hiftorical {ketch of mines we fhall add fome con» jetural remarks concerning their formation. Thofe ores which are found under water (I); upon the furface of the earth (III.) ; in fiffures of mountains and fubterranean c2- vities, accumulated, but not accreted to the contiguous rocks, (IV. 4.) feem from their loofe, unconnelted, broken appearances to have been conveyed by alluvion. All martial ochres have probably been {cparated from vitriolic ferruginous waters (11.) either {pontareouily or by calcareous earth ; and thefe waters fecm to have acquired their metallic con- tents by diffolying the vitriol which is produced by the fponta- neous decompofition of martial pyrites. The ochres of coppers inc, and perhaps of feveral other metals, have probably been precipitated from vitriolic waters by {ome fubftance, as calcare- ous earth, more difpofed to combine with acids; and thefe vitri- olic waters have probably been rendered metaliiferous, by dif- Aplving the yitriols produced by a combufiion of cupreous pyrites, ¥ 0 Ra and re —————— ORE g either in jes natural flags. gree of purity, poflefled &f 2]] js Properti £2ged with fome other metals in cettain minerals, and of the ore of zinc called blend 5 for thefe minépals are not, as martial pyrites is, fufeeptible of decompofition fpontaneonfly, that j3, Y airand moifture, ¢ metalliferous nog, and poss (TV, aqueons men cryftallized diftinéily, ame fluid, The earths a were alfy probably in 3 fof ftate while th he opake-colored ftones feem to have r metallic calxes mixed and diffufed thy nd flones uniformly colored by metals (IV. 2, ey received thefe tinges. eceived their co] ough the {oft lapideous ftones have probably re« in water, appears pro- rms, but alf ) lized fo reous: earths, contained ip which water thefe ftones . € veins called cumuy Jerous the harde lated, (Iv, 5 mountains (1V. 6.) are belie £0Us to the nodyjes (IV. 1). €eém to have been originally for where they are found, he metalliferous firata (IV, 3.) have between the lapideous fir cach other by fome violen We fuppofed that the clay twixt the fevers] trata of 0 Derbyfhire. he matters infinuated may have been either fluid, which would after. wards cryfallize, znd form entire regalar mafies ; of they may ave been the ruins of and veins bye 2 vaters, and there ( cafe they wij] broken ang Irregular,” Th i quently confounded with diflinguifhed, aceordj ing Propertizs: j. than the veins calle greater depth than .) and the ved by Walle;iys to be anal. Thefe metalliferoy probably been infinuated ata, after the fe paration of thefe from fame manner firata epoli -* €y are feldom fo, 1d generally in the neigh. bourhood ‘RE S oe 1 0 one is called native or virgis 1d which is found al ) ~The go ‘received their , bl have x : of veins, from which they proba ulation called f: re bourhood of veins, heir want of the thiner terpofed betwixt t contents. 3. From ges d, are frequently heir want of the other brie, which, we > its matrix ; and from ks exift' of ore rks exi ck and the . noeft ma ] propertics of eins. perly fo called, es tdi a in weins, pr an broken ap- But in eins, P h e concreted, . ular, un . '. ing been ther ftate. ‘Their reg ither immedi- ores having heir prefent ftate. 1 us reck, eit £ n their pre he contiguo earance o depofited in! cretion to t . he regular appeara of their acc 2 { a matrix, t ftallization CAC © Latervantion of # Bregen C elit or b inter , ore the q in indicate ae mtr invelopng the ¢ contents * nt concret- 1d of the id contents, hav the ore ar he other foli } lefts swell as t id ftate. ndicular ¢ oom a fluid to 2 folid fat veins, and pie perp? ave been pro- € believe, : d Fiffures, : ly as $ alle ns only Moit author f mountains, ¢ confider vei vd . : § ftrata 0 ather, they ther believe, in the ftony caufe; or r They fur . fre Mo ey metalliferous wl by the exficcation Wallorios fiflures fille have been occafi . folid ftate. hat s have fluid to a jon. but tha that fiffures fling from a from exficcation, d i fe were pa i formed fro ile yet foft an while the s have been ftrata, while y t- . hat fifTure hrough the ftrata, firata penetra thinks, t Is made through of the fir He : channels fluid parts id parts. veins were by the more more folid parts. . ater, or by hrough the ir metalliferous fluid, by wat a paflage throug d thither their m ted ing and forcing id parts conveye ated ‘or concreted. thinks, that thefe fluid par were there coagulet the veins of ys ontents, W bferving, ; that the and ftoney cont inion by o each other; imes ts his op arallel to in is fometime He f{uppor rally run p fame vein re fame Bape Eo peivend courfe 3 that the a are frequently ter, nN - - N . - t a frequently be imes dilated ; that r veins ; contracted and oo lic of divided into prod fi sag © . being than at ’ 11 whic - minated by “der at bottom below : a . tly wider ery narrow d by exficca are frequen and are very n produce h ‘ ideft at top, d not have been p had a different, always wi : could n have ha pearances, he Sinks, os fiffures appear ins crofled by pies, tion. From thefe WEE and rupture of ye Whether Muy he disjun igin than veins. tion of thele and from t da later orig d al exficca have ha 4 very gra u thev have they feem to h uced by the or ; or whether the could have Ee coherent Oe nT earinuteos; o r rong iolent cauies, lv foun large mafies o by the fame vio eneraily or yt 2 ich fiffures are g iferous mou been produce in which ich metallifero! b . he ftrata d by which i aifed above by which t anged, an ir frata r 1 bon broken and der a formed, or the ith ereat probability, : elves have ' have, with g tains Shomich I: as fome others te +ir original level ; to determine. . ih o Ig d; I do not pretend conjectures Veins v . joined, ch are n In th Vein reafon as, on feldom, mounta ch ma if ever ans we Y not im ’ found but in accefs to hr obably be, that 1 ore ancient g m m n rata any depofiteq early horizo ele m . Ountains much ns, brok ita ? w leat, the veins hs and dif. €1s inter. fupted, O RE 8 kinds of ftones, principally in flints and quartz. Mr. | Crater rupted, more extended, and confequently more valuable to miners than the veins in lofty, craggy, irregular, and fhattered moun- tains. . hd . Nh Authors difpute concerning the time in which ores have been formed, fome referring it to the creation of the world, or to the firft fubfequent ages; =ad others believing, that they have been gradually from all times, and arc NOW daily, formed. From the accretion of ores and of their matrices to their proper rocks, and from the infertion of metalliferous nodules and ftriz in the hardeft ftones, we are inclined to believe, that the matter of thefe veins and nodules are nearly coeval with the rocks and ftones in which they are inveloped. Neverthelefs, we cannot doubt that {mall quantities, at leaft, of ores are fill daily formed in veins, fiffures, and other {ubterranean cavities. Several well attefted infances confirming this opinion are adduced by authors: Cron- fledt mentions an incruftation of filver-ore that was found adher- ing to 2 thin coat of lamp-black, or of {oot, with which the {moke of a torch had foiled 2 rock in a mine at Koningfberg in Norway ; and that this incruftation of filver-ore had been formed by a metalliferous water pafling over the rock. Lehman affirms, that he poffefles fome filver-ore attached to the ftep of a ladder, bund in a mine in Hartz, which had been abandoned two hundred years ago ; and that feveral fteps of ladders fimilarly en- crufted had been found. Many other inftances are mentioned by authors, of galena, pyrites, filver-ores, and other metalliferous {ubftances having been found adhering to wood, to foffil-coal, to ftalaitical encruftations,. to oylter-fhells, and other recent fubftances. From thefe, and from imilar inftances which I have feen, I am induced to believe, that not only ochres and frage nents of ores may, with other alluvial matters, be now daily de- pofited, but alfo that {mall quantities of mineralifed ores are re- cently formed; although many hiftories mentioned by Becher, Barba, Henckel, and other authors, of the entire renovation of exhaufted veins, and efpecially thofe of the growth and vegeta~ tion of metals and of ores, appear to be at leatt doubtful. * Various opinions have been publifhed concerning the formation of mineralifed ores. According to fome, thefe ores were formed by congelation of the fluid maffes found in mines, called Gubrs. See Gunr. Other authors believe, that ores have been formed by the condenfation of certain mineral, metallic, fulphureous, and arfenical vapors, with which they fuppofe that mines abound. Some have even affirmed, that they have feen this vapor con- denle, and become in a few days changed into gold, filver, and other metallic matters. It has been above obferved, that from feveral appearances which occur in veins, there is great reafon to believe, that ores have not been carried thither and dcpoil ted in SE I their re ————— — ————— — a — — O'R Ek s Cramer fays, that the yellow brilliang fpots of ne, called /zp; lazuli, “are native golq ; L ¢r und which S) at the fame enfate for the 1S to be found ected in hol- ir feyera] bend- S bya naturjy] confiderab]je q in France. to compenfate thoi that he gave [jy France which cop the Rhine, the Rhone, the D the Arriege, the Garonne, ITiege called Ferriet 5 rivers their Prefent flate, py; have beep that js, changed fron, 4 fluid to 5 of the metalliferoys op, Veins, may have been Occafioned ejthey Solved iy watery if t] aving be hey were capable of fych folution, “or by their €n raifed in form of fubterraneqp fires, For Ho difpofition ¢o Cryftallize j ubftance thy; i fluid ing melted by fire or by being reduce ores have hee, for through the crack 2 , of mineralifed earthquakes whic terranean fires, s in the iutervening ftrata, occafioned by thee h have, in 5 fingular Manner, broke , the ftrata of aetalliferoys nd derap ged- ountries, apd which, 5 has beep above remarke » have beep probably Occafioned by, at Jeapt have certainly peep always accompanied with, fubterranean fires, r) Concerning thefe, zz I, PIs Lazyyg, | The 3 the blue but thefe apc very - . . 0 . ve S d a . nd of the Rhone; than thofe of the Whine find gold to the articles are WE days a peat nl find any. ers Pad fays, ho and in others Lr elfewhere is never ber . ' in rivers 7s contal value of a pi old found in river ts. Italwaysc he native g tv-four kara v, lv filver. fectly pure, a, WY a ay : in uanti dine to r. ts, that o he Sold of or rivers, tn co owen wo karts being the Sound to be from cig ft, and that of t ez pureft. ( 5) ‘ . iffolved dire&tly di - Although gold cannot il the pivaiyeinios (s) Ores oO ably may be has no proper ore of €0 is et it pr Thus, altboug s, in which it by fulphur, Ti matters. ' eral fubftances, nantity etallic in feveral mineral uch larger quan: of other m it is found in s, witha m 3 ineralifed : et 1t 1s 1 amer affirms, r attributes its wi Shways ccompanie, ae that 25 AEE oprats, and alwa hich lat .« old are . f arfenic, ; tow taining g : hite ore 0 of filver ; inerals con . innabar, w a he min tumony, Cl lled galen : fate. The re of an cad-ore ca : other it Bhat anes edad in some hormblend. Gold vitreous an ently mbt ¢ and in horn , vison: is more Baqumy in limeftone do not form regular atrix 3 but itis a al very Da) through a ma, om ines are in ed uniformly fio fand is entirely ar el ris tt hink, tha 3 colored fe : veins, nO d Cramer t and vialetec that in her an d, black, llot relates, ! pe The yellow, Tot io gold. Mr. gai oF 93522 5 ds, are faid to be kind of fand, fo to 844 grains of no d in effays of pee each time fm 54 ained in the feorta 5 tain nich remair nd tac re- . were 0 old w . re gold, a gran exclufive oF ined two-thirds — fand taken up that of the metal oe? He fays, that Fined very unequal pro. ning third was , from each other cont ot iftanc y hat w {mall difta re than that portions 0 5 found in fands 1s g Reaumaur 25% 1 Academy at he go A id matris. he Rova . is if i imbedded Bs Jo ne was fhewn different finenefs in dif. oold, weighing $4 nd upon eflay to have hods Es which was ound be cffayed by the mes = ’ mafs, oe the ferent pares of tie containing geld from roe by why in Ores an tration of go Ores): or the { ander . for the ex . MELTING of : : teft place u 8 Sohn matters fe on fuled in a apd] 02 placed in an Ai General be effayed by bei a ol Tead, if they 0 genera fle of an eflav-fur times their quantity 0 eafily the mu . teht or ten - ith eig furnace, Ww A. Platina is very fare; and hae Sy like gold, jt Cannot be 3). y. no ore Properly According] > I Namely, Platina js found native metallic fata. ext t -R. to gol ralifed by h i OF Virgin $ to be feparateq from er diredted in th the lead € articles, Essays , 4 of Gorp, Th i et in a forge. till the fcoria hay ac- has imbibed the noble 4 for Yaying auriferous Sands, S » ative Silver is form of > OF cryflallizeq, It Ij found jj » and jin f 165 generally Qny cryft, lver ores, Iis fome. Three ORE S ich known, whi inal proper ores of flver ure or 1 C1 ‘neile ’ n ep ye Th Si pr The ry the color ’ foftn Spe Rares o by DE Tt is very heavy, and so he Me mia lead. It is filver. In thiso ifts imitate it very 3 i f pure \ ert arti : rucible. (u weight 0 Some exp fufion in a crucl led lone. . filver by u . re is {fo Ca fulphur a fulphur with fi This ore bles . n u p hlver ore. he h it refem somal ls horny or pk wo er by i BM heated, fr or its color and fem This ore, being with a gentle heat. horn or colophony. ores do, and he ineralifed by fulphur ackles, as almo filver, which are pr allerius fays, after Two-thirds of rare is very ey baun-Géorgen- Stadt in ar 18 0 . . 3 d at and arfenic hat it is foun rs dward, t ts color is mor Veo (x) led alfo Roficlare. oT and is Saxony. ed filver ore, cal 44 cryfallized, re ore the filver . ret tim thi or 1g red 3 4 “bone mention ir but chiefly by He fufible like the arfenic and y iu d furnifhes two- is mineralifed by arie little iron, an d either from former. Iralfo oY red color may POF arfenic and ful- its weight of oto or from the mixture the iron it co ording to Cron determinate fig u) The. witreous or a erytallized, or has of fulphur to one part es or of fibres, ’ adding about five pares of the fulphur is con- 3 Pay be imitated by which operation fing a plate of filver red-hot filver ; 1n wh d by expofin of melted fi ay be imitated by own, yel- fumed : or J urning BE ors 3 white, pearly, brown: Itis to the fumes ore has various “foliated and femi-tran Be us . t 1s foli anale. (x) Corns or reddifh. ltis ith the flame of ac d blue flame, low, greenifh, and fufible wi fulphureous an {eni- duétile, ius fays, a lulp tity of an ar fomewhat dud as Walleriu {mall quantity o f filver mits {oa very fm: -thirds of filver, hevtsd; hs ng to Cragar, 3 it gontans Enishi gry and, Wallerius fays, f falphur, and ith a little arfe- cal fame, fiderable quantity of is filver united wi or filver with a confi thinks, that it ;t it is a luna cornea, : de- ic. Lehman s, that 1t 15 2 le of being de wig Mr, Sroniads Sexe that 1t 1s ha acid. This combined but by fabllances which robable, 2s the ore A but y he molt pro ? d as it cann compofed, {eems to be the luna cornea, an ic with filver. latter opinion lc is fimilar to and of arfenic eed : fcription, I f fulphur, . hich are emit Be by any nd the fell flightly arfenical, w every combina- Im an {o obferva ’ ifton. he blue flame, e, are alfo utaining phlogi mom eet oen s le ttomlle os tion of. marine | phur; OREGQy Ys from the only j larger quantity of on (0) Red fil, requently Fite 10a deep red, accor fparent, 1; or folid, or cryfaffiveq | a + Its color jg ya: ryfiallized, 5 po dmger Ie crackles Si the Proportions of 1h from a dark grey » an, 18 . ca 8S 1 i rye hornbieng,” "1° It is found gone: a z) Befides the ¢ hy: ores ¢ : ree filver. Con filver mixed wich ores ahoye defcribed This : Other meg). containg phur; and Copper and . } Hf idly ¢, generally more of & Fiver mineralifed 13 valued chiefly for th ormer than of Iver ores. ¢ filver, jt has s the following ’ arfenic C : » Copper \ part of filver, ay on, fome. Ng to Wal. . 5. P o alphur 2 ralifed p G - In this blend £1 > arfe. the gold J fu iphur, Probably or ing Bold and zinc phur, © ZINC are rendered capable of" of iron, 6. Si . Of un rosie: Dyetls frequently found i 4 s IN the red nd in #7, irom, and ef] in black and ble 4p are mine. iting with (he fr" r, . by an alia); on Julti pretends concerning ji ¢ Sulffance ; ine mager, ) ¥ O R ES Jilver—#re, which is only a lead-ore containing much filver, an Ores of filver may be ¢ffayed { Jee the articie Bssax of Ores] by the iame methods which are employed for the extraétion of that metal from large quantities of ores ; which methods are dif- ferent, and fuited to the different qualities of the feveral ores. (See SMELTING of Orgs.) Or, in general, ores and earths con- taining filver may be eflayed by the following Procefles, which are copied from Dr. Mortimer’s Englifh edition of Cramer's Art of Afayirg Metals, Part ll. Proces 1. PROCESS L To precipitate Silver by means of Lead from fufible Ores. «« POUND the ore in a very clean iron-mortar into fine pow= ¢ der: of this weigh ore docimaftical centaer or quintal, and ¢¢ eight of the like centners of granulated lead. «Thea have at hand the docimafical telt (zz Prare L.); ¢ which muft not as yet have ferved to any operation : pour into « it about half of the granulated lead, and fpread ii with your ¢¢ finger through the cavity of it. «« Put upon this lead the pounded ore; and then cover it quite ¢¢ with the remainder of the granulated lead. ¢¢ Pur the teft, thus loaded, under the muffle of an effay-furnace, ¢ and in the hinder part of it: then make your fire, and en- « creafe it gradually. 1f you look thro’ the holes of cither of ¢¢ the fliders, you will foon fee that the pounded ore will be raifed <¢ out of the melted lead, and {wim upon it. A little afier, it “¢ will grow clammy, melt, and be thrown towards the border of ¢¢ the teft s then the furface of the lead will appear in the middie of ¢¢ the telt like a bright difk, and you will fee it fmoak and boil : fo «« {oon as you fee this, it will be proper to diminifh the fire a {mall ¢¢ matter for a quarter of an hour, fo as that the boiling of the ¢ lead may almoft ceafe. Then again, encreafe the fire to fuch 2 ¢¢ degree that all may turn-into a thin fluid, and the lead may be «¢ {een, as before, fmoaking and boiling with great violence. «¢ The furface of it will then diminifh by degrees, and be covered ¢¢ over with a mafs of fcorias. Finally, have at hand an iron hook ¢s ready heated, wherewith the whole mafs muft be ftirred, efpe- « cially towards the border 3 that in cafe any {wall parcels of the sore, not yet diffolved, fhould be adherent there, they may be s¢ brought down, taking great care not to fir any the leaft thing ¢¢ out of the teft. i) ¢« Now, if what is adherent to the hook during the Rirring, ¢ when you raife it above the teft, melts quickly again, and the ¢ extremity of the hook, grown cold, 1s covered with a thio, ¢¢ fmooth, fhining crult ; it is a fign that the fcorification is per- You, 1k S “ felt; ORE ss and od the gry filver-ore, which j 1S a copper-ore Containimg- ORES . you rent to the hook, ° the teft, without anda continue the fire . bi: i oy i It, and with a Ja¢ Y 101s or mixture of , le put it again j ; again int ““ In the f3 ny foreign b me degree till the feoria bas reqs € the abov. . . c-me ny e . ““ teft with 5 parr oc qualities. This d its perfection, ang “ pair of tongs once obtained Lk ‘ gether with the frorinf out of the fire, and pour th ’] ad. (he “and rubb - Wimmin is € lead, to- ed wich . 8 upon it, int ’ ** procefs tallow. Thus will the firg operatic pade hor . ration of the. be perfo ; * above hp rmed, which does nog commonly, indeed, | ’ eed, laft oR quarters of an hour, gain examine w a perfe&t fcorification 3 hr ““ that the filver tf they have . as been iitated 0 May thence “ rias, and recone] by hb poipitated out of the ore taraed nde > the feorification la s the lead “ Iver remaj and the veflels pb the fire muft be mod ams at the “¢ they f € extremely good, o erately fupplied, lm io gf Ps eo enough : be brought to an end atic flipated by that the filver is di corroded ore, and can hardly “ confiderably, 56 1 Hi In this procefs, the fu] 4 en the ore is broken {mall bi dessin, are in part eafj Ha forbed by the [ead : +¢ upon the heavi J Phur which js j u Riolence of fire, it turns into oJ vis predominant in the ore 2 = Into a very penetratin Jefficacy, unlefs th pher and wi 0 o fcorias - 5 plumbeous f and very fufible glah, hy ¢ arlenic lies hidden in 4 whi but when arfenjc urns Immediately having adiffolvin te pyrite or cobalr, ‘ For ORE S ORES of COPPER. Copper is found undér « For this reafon, the fixed part of the ore, which is no filver, is ¢« diffolved by that glafs, melts, and affumes the form of fcorias, ¢¢ The unmetallic earths and the pure copper or lead-ores thereto k¢ adherent are of this kind. The filver then remains immutable, «¢ and being freed of thefe heterogeneous bodies, which are partly ¢« diffipated and partly melted, “it is precipitated and received ¢¢ by the remaining regulusof lead. Therefore this procefs is com- ¢¢ pleted by three diftinét operations ; viz. 1. By roafting. 2. By ¢¢ {corification. 3. By the melting precipitation -of the filver, «¢ which is the refult of the two former operations. «The ore muft be pulverifed very fine in order to encreafe the t {urface, that the diffipation of the volatiles, and the diffolution by ¢¢ litharge may be fooner effefled. This pulverifing muft then be «¢ done before the ore is weighed, becaufe there is always fome part i¢ of the ore adherent to the mortar or iron-plate on which it is «« made fine ; which part being Joft, the operation is not exact. «¢ Erker was in the right when lie prefcribed eight centuers of lead ¢¢ for the fubduing of fufible ores. Neverthelefs, it mult be owned ¢« that this quantity is fuperflucus in fome cafes, However, as the «¢ fluxibility of the filver-ore depends from the ablence of ftones; ¢¢ pyrites, &c. it is ealy to fee, that there are an infinite number « of degrees of fluxibility which it would be needlefs to determine ¢« exaétly, and moft commonly very difficult to determine by the s« bare fight, Befides, a little more lead does not render the pros ¢¢ cefs imperfet ; on the contrary, if you ufe too {mall a quantity « of lead, the fcorification is never completely mide, Nay, there i¢ are a great many ores, containing fulphur and arfenic in plenty, « that deftroy a confiderable quantity of lead fuch are the red é filver-ore, and that wherein there is a great deal of the fteel- « grained lead ore. If the fire mult be fometimes diminifhed in «« the middle of the procefs, it is in order to hinder the too much ¢¢ attenuated licharge, which is continually generated out of the et lead, from penetrating the pores of the tefl, and from corroding ¢¢ iv ; which is cafily done when the fire is over-ftrong ; for then ¢« the turface of the veffel which is contiguous to the lead contraéls «¢ cavities, or beiog totally confumed by fmall holes, lets the t¢ regulus flow out of it. The veflels that ate moft fubject to this «+ inconvenience are thofe, in the materials of which lime plafter e« and chalk are mixed. Nay, thefe bodies, which are of their « pature refradiory, being eroded during their {corification, at é the {ame time communicate a great clamminefs to the {coria ; «¢ fo that a great quantity of the mafs remains adherent to the eft é¢ in the form of protuberances, when you pour it out ; whereby $a great many grains of the regulus are detained.” g 2 PROCESS “ ] OREG§g in three different forms, ‘dhder ground I. Nitive or’ PROCESS pp. THE regulus obtained by the Proce fs L contai of the ore, ang the unfcorificg part of the lead, T 2fterwards feparated from | Zion ; which 1e lead, and obtained Procefs is deferibed un Pure by cupe/jy der the aricle of the Dictionary, SSAY of the VaLug 9 SiLveg, ns all the filvep he filver may be PROCEsgs 111, Sver-ore canyes be 4 be vendereq res the fcorification of d by the procefs J. -I3Mer therefore direéts th i OWing manner [re ““ Bruife the ore j €ntners of the teft yp. it a flrong fire, ¢ » diminifh the v * It fometim ““folved by lith * of pitch, fwj “¢ which are 3) arge ; felves *s fhut the fire ; then gently touch with a fmal] iron cold hook, "to which jit ; take it off {ofily, not to Jofe any to a fine powder, adding a |i tle glafs of Jeg “Put it again into the teft ; then continue the leorification *“ 1s brought fo irs erfeCtion, B & P fufpe&t,. d the fcoria ing a fine duft,. 4ud thus the g ““ of metal wij] appear, if there are any left ; becaufe they can. ** never be poynde fine, The flyer is feparateq from this regu. es by eoppelling, as in Proce; 1. “ Al ORE § : : ore ich is much more er diverfely ramified, which rare «@r virgin copper * Ithough in the fire ;_ for, altho i- are refraltory in that are vitrt ‘« All said ° Bn hs in hy a: mls «¢ fome of them helefs, all the others, a become fo thin in the «¢ fiable do; neverthelels, metals, and neverbecc of a precious " igble more diledily iy 3 fufficient pres HEA diffolve thefe «¢ fufion as 1s requ itfelf does not con lefs you add fome, «¢ metal. But Hihmge Te help of Ave Hones rt the faid «¢ refractory Be to them; for the ny the refraltory ore, ¢¢ mechanical mix through the interftices fs is produced, which Rig Sp Sg orion by the litharge. You may «¢ and begins to dx farther dilution by ¢ on meallic éales ; «4¢ hardly admits 307 make colored gla Sy gives a color, you 4 fe 1¢ platu, 3 elefsly upn, the. A died on every fide, « if you pour car in that they may be eq hole days together in a «¢ will moves wy torture them for w n never be diluted by «¢ even altho Ne glafs already made ca Wherefore, you mult «¢ great fire. hs and litharge upon 1t. the making of the moft “< only Be tific of glafs-makers, fia they put the fpecies of << ufe the arti reat care De sca) mixture pre- «« perfect gal, tke, gr fire, to hava 2 mackie) ; which is done «¢ their ingredicn accede, during the on the ore: bat if you «¢ cede, or at Juels» glafs of lead mixt wit ntly fufible, you may <¢ here by poundi x of lead is not fufficie oufided Tito afine I as melted firlt, and then p fire than ¢¢ add to 1t. nd a greater fire tha «¢ powder. ification requires a longer a harge is m re- 2 As this Foridaagion a greater guandiy oF fi ay to fee “the Fore Tubdue tie gefialiory Sori ufed here a i ¢ over requilite antity of lea i it 1s neverthelefs «¢ why a much greater Diels lends often Shainin be neceflary ; “ Praca], 0d ah i are greateit quantity t to try fo many times © proper ie p ’ it fhould' be naar to filver the lead, «¢ left, for inftance, make it evident ed you fear left any + the lead lone, & in the coppel. Jor nes ried the cop- ¢ when veer be taken away b I put in execution } for you <¢ thing 0 : ling duly " filver out of the col- «¢ pels be good, and the cope quantity of fi Yor coppelling, #3 46 can hardly soltel 2 which rifes during into the coppel.” = lofled fume a that is withdrawa ¢¢ well as out © PROCESS IV. i that yd Cramer direfls, refraddory by pyrites ing manner. IF the pe whip Ger by lead in the following the filver thou © ¢ Break [drt 0 Affaying, Part 2. pr H hute, Hy when the Veni er 1 € ceafe be aye Fr HH e til] th yr UCS to {nly art © “ ne at {er ' put, YY €< of the vible boried which oe Ly the fulphoy ot : e ; | take aw: 10ak, of th Vill know fiom sb or the way th e {mel] of . FOM the colo, “ the teft Ud of garli Mm tiie ceffatio ma . , J and 1 rev vres . C, or +1 wi i n ay cool of itfe]f, AVE 1tin 4 place poy ow AE then it ) : 0 cold. 1 . . ’ Without “oan y : > tnat at tle p ay what is adherent ’ ie roafted ore. an se : owcer, z . it to the v te, Ana with : “@ pg efiel « - *¢ gis of lead ; and re find is together vellel pound it 10 4 ame teft . y, {corify tl than egy) Jud LU wher ) 10nty the equal weigh tracted chin ein the tel whole collie ght chin Cillng w > Collected ore ; emarhs oo was deferib.q jy poids anlefs it ou in of {i : OW pyrites. cefs IJ, "Un.